Liquid-crystalline media

ABSTRACT

The invention relates to liquid-crystalline media which can be used, in particular, for electro-optical displays having active-matrix addressing based on the ECB effect and for IPS (in-plane switching) displays or FFS (fringe field switching) displays.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Application DE 10 2011 121665.4, filed Dec. 20, 2011, which is incorporated by reference herein,in its entirety and for all purposes.

FIELD OF THE INVENTION

The invention relates to liquid-crystalline media which comprise atleast one compound of the formula I,

in which

-   R¹ and R¹* each, independently of one another, denote an alkyl or    alkoxy radical having 1 to 15 C atoms, where, in addition, one or    more CH₂ groups in these radicals may each be replaced,    independently of one another, by —C≡C—, —CF₂O—, —CH═CH—,

-    —O—, —CO—O—, —O—CO— in such a way that O atoms are not linked    directly to one another, and in which, in addition, one or more H    atoms may be replaced by halogen,-   Z¹ denotes a single bond, —CH₂CH₂—, —CH═CH—, —CH₂O—, —OCH₂—, —CF₂O—,    —OCF₂—, —COO—, —OCO—, —C₂F₄—, —CF═CF—, —CH═CHCHO—,-   L¹ and L² each, independently of one another, denote F, Cl, CF₃,    OCF₃ or CHF₂.

Media of this type can be used, in particular, for electro-opticaldisplays having active-matrix addressing based on the ECB effect and forIPS (in-plane switching) displays or FFS (fringe field switching)displays.

BACKGROUND OF THE INVENTION

The principle of electrically controlled birefringence, the ECB effector also DAP (deformation of aligned phases) effect, was described forthe first time in 1971 (M. F. Schieckel and K. Fahrenschon, “Deformationof nematic liquid crystals with vertical orientation in electricalfields”, Appl. Phys. Lett. 19 (1971), 3912). This was followed by papersby J. F. Kahn (Appl. Phys. Lett. 20 (1972), 1193) and G. Labrunie and J.Robert (J. Appl. Phys. 44 (1973), 4869).

The papers by J. Robert and F. Clerc (SID 80 Digest Techn. Papers(1980), 30), J. Duchene (Displays 7 (1986), 3) and H. Schad (SID 82Digest Techn. Papers (1982), 244) showed that liquid-crystalline phasesmust have high values for the ratio of the elastic constants K₃/K₁, highvalues for the optical anisotropy Δn and values for the dielectricanisotropy of Δ∈≦−0.5 in order to be suitable for use inhigh-information display elements based on the ECB effect.Electro-optical display elements based on the ECB effect have ahomeotropic edge alignment (VA technology=vertically aligned).Dielectrically negative liquid-crystal media can also be used indisplays which use the so-called IPS or FFS effect.

Displays which use the ECB effect, as so-called VAN (vertically alignednematic) displays, for example in the MVA (multi-domain verticalalignment, for example: Yoshide, H. et al., paper 3.1: “MVA LCD forNotebook or Mobile PCs . . . ”, SID 2004 International Symposium, Digestof Technical Papers, XXXV, Book I, pp. 6 to 9, and Liu, C. T. et al.,paper 15.1: “A 46-inch TFT-LCD HDTV Technology.”, SID 2004 InternationalSymposium, Digest of Technical Papers, XXXV, Book II, pp. 750 to 753),PVA (patterned vertical alignment, for example: Kim, Sang Soo, paper15.4: “Super PVA Sets New State-of-the-Art for LCD-TV”, SID 2004International Symposium, Digest of Technical Papers, XXXV, Book II, pp.760 to 763), ASV (advanced super view, for example: Shigeta, Mitzuhiroand Fukuoka, Hirofumi, paper 15.2: “Development of High Quality LCDTV”,SID 2004 International Symposium, Digest of Technical Papers, XXXV, BookII, pp. 754 to 757) modes, have established themselves as one of thethree more recent types of liquid-crystal display that are currently themost important, in particular for television applications, besides IPS(in-plane switching) displays (for example: Yeo, S.D., paper 15.3: “AnLC Display for the TV Application”, SID 2004 International Symposium,Digest of Technical Papers, XXXV, Book II, pp. 758 & 759) and thelong-known TN (twisted nematic) displays. The technologies are comparedin general form, for example, in Souk, Jun, SID Seminar 2004, seminarM-6: “Recent Advances in LCD Technology”, Seminar Lecture Notes, M-6/1to M-6/26, and Miller, Ian, SID Seminar 2004, seminar M-7:“LCD-Television”, Seminar Lecture Notes, M-7/1 to M-7/32. Although theresponse times of modern ECB displays have already been significantlyimproved by addressing methods with overdrive, for example: Kim, HyeonKyeong et al., paper 9.1: “A 57-in. Wide UXGA TFT-LCD for HDTVApplication”, SID 2004 International Symposium, Digest of TechnicalPapers, XXXV, Book I, pp. 106 to 109, the achievement ofvideo-compatible response times, in particular on switching of greyshades, is still a problem which has not yet been satisfactorily solved.

Industrial application of this effect in electro-optical displayelements requires LC phases, which have to satisfy a multiplicity ofrequirements. Particularly important here are chemical resistance tomoisture, air and physical influences, such as heat, infrared, visibleand ultraviolet radiation and direct and alternating electric fields.

Furthermore, industrially usable LC phases are required to have aliquid-crystalline mesophase in a suitable temperature range and lowviscosity.

None of the hitherto-disclosed series of compounds having aliquid-crystalline mesophase includes a single compound which meets allthese requirements. Mixtures of two to 25, preferably three to 18,compounds are therefore generally prepared in order to obtain substanceswhich can be used as LC phases. However, it has not been possible toprepare optimum phases easily in this way since no liquid-crystalmaterials having significantly negative dielectric anisotropy andadequate long-term stability were hitherto available.

Matrix liquid-crystal displays (MLC displays) are known. Non-linearelements which can be used for individual switching of the individualpixels are, for example, active elements (i.e. transistors). The term“active matrix” is then used, where a distinction can be made betweentwo types:

-   1. MOS (metal oxide semiconductor) transistors on a silicon wafer as    substrate-   2. thin-film transistors (TFTs) on a glass plate as substrate.

In the case of type 1, the electro-optical effect used is usuallydynamic scattering or the guest-host effect. The use of single-crystalsilicon as substrate material restricts the display size, since evenmodular assembly of various part-displays results in problems at thejoints.

In the case of the more promising type 2, which is preferred, theelectro-optical effect used is usually the TN effect.

A distinction is made between two technologies: TFTs comprising compoundsemiconductors, such as, for example, CdSe, or TFTs based onpolycrystalline or amorphous silicon. The latter technology is beingworked on intensively worldwide.

The TFT matrix is applied to the inside of one glass plate of thedisplay, while the other glass plate carries the transparentcounterelectrode on its inside. Compared with the size of the pixelelectrode, the TFT is very small and has virtually no adverse effect onthe image. This technology can also be extended to fully colour-capabledisplays, in which a mosaic of red, green and blue filters is arrangedin such a way that a filter element is opposite each switchable pixel.

The term MLC displays here covers any matrix display with integratednon-linear elements, i.e. besides the active matrix, also displays withpassive elements, such as varistors or diodes(MIM=metal-insulator-metal).

MLC displays of this type are particularly suitable for TV applications(for example pocket TVs) or for high-information displays in automobileor aircraft construction. Besides problems regarding the angledependence of the contrast and the response times, difficulties alsoarise in MLC displays due to insufficiently high specific resistance ofthe liquid-crystal mixtures [TOGASHI, S., SEKIGUCHI, K., TANABE, H.,YAMAMOTO, E., SORI-MACHI, K., TAJIMA, E., WATANABE, H., SHIMIZU, H.,Proc. Eurodisplay 84, September 1984: A 210-288 Matrix LCD Controlled byDouble Stage Diode Rings, pp. 141 ff., Paris; STROMER, M., Proc.Eurodisplay 84, September 1984: Design of Thin Film Transistors forMatrix Addressing of Television Liquid Crystal Displays, pp. 145 ff.,Paris]. With decreasing resistance, the contrast of an MLC displaydeteriorates. Since the specific resistance of the liquid-crystalmixture generally drops over the life of an MLC display owing tointeraction with the inside surfaces of the display, a high (initial)resistance is very important for displays that have to have acceptableresistance values over a long operating period.

There is still a great demand for MLC displays having very high specificresistance at the same time as a large working-temperature range, shortresponse times and a low threshold voltage, with the aid of whichvarious grey shades can be generated.

The disadvantage of the MLC-TN displays frequently used is due to theircomparatively low contrast, the relatively high viewing-angle dependenceand the difficulty of generating grey shades in these displays.

VA displays have significantly better viewing-angle dependencies and aretherefore principally used for televisions and monitors. However, therecontinues to be a need to improve the response times here. However,properties such as, for example, the low-temperature stability and thereliability must not be impaired at the same time.

SUMMARY OF THE INVENTION

An embodiment of the invention relates to a liquid-crystalline mediumwhich comprises at least one compound of the formula I,

in which

-   R¹ and R¹* each, independently of one another, denote an alkyl or    alkoxy radical having 1 to 15 C atoms, where, in addition, one or    more CH₂ groups in these radicals may each be replaced,    independently of one another, by —C≡C—, —CF₂O—, —CH═CH—,

-    —O—, —CO—O—, —O—CO— in such a way that O atoms are not linked    directly to one another, and in which, in addition, one or more H    atoms may be replaced by halogen,-   Z¹ denotes a single bond, —CH₂CH₂—, —CH═CH—, —CH₂O—, —OCH₂—, —CF₂O—,    —OCF₂—, —COO—, —OCO—, —C₂F₄—, —CF═CF—, —CH═CHCHO—,-   L¹ and L² each, independently of one another, denote F, Cl, CF₃,    OCF₃ or CHF₂.

Media of this type can be used, in particular, for electro-opticaldisplays having active-matrix addressing based on the ECB effect and forIPS (in-plane switching) displays or FFS (fringe field switching)displays.

DETAILED DESCRIPTION OF THE INVENTION

The invention is based on the object of providing liquid-crystalmixtures, in particular for monitor and TV applications, based on theECB effect or on the IPS or FFS effect, which do not have thedisadvantages indicated above, or only do so to a reduced extent. Inparticular, it must be ensured for monitors and televisions that theyalso work at extremely high and extremely low temperatures and at thesame time have short response times and at the same time have animproved reliability behaviour, in particular exhibit no orsignificantly reduced image sticking after long operating times.

Surprisingly, it is possible to improve the rotational viscosity valuesand thus the response times if one or more, preferably two, polarcompounds of the general formula I are used in liquid-crystal mixtures,in particular in LC mixtures having negative dielectric anisotropy,preferably for VA displays. With the aid of the compounds of the formulaI, it is possible to prepare liquid-crystal mixtures, preferably VA,PS-VA, PSA, IPS and FFS mixtures which have short response times, at thesame time good phase properties and good low-temperature behaviour.

An embodiment of the invention thus relates to a liquid-crystallinemedium which comprises at least one compound of the formula I,

in which

-   R¹ and R¹* each, independently of one another, denote an alkyl or    alkoxy radical having 1 to 15 C atoms, where, in addition, one or    more CH₂ groups in these radicals may each be replaced,    independently of one another, by —C≡C—, —CF₂O—, —CH═CH—,

-    —O—, —CO—O—, —O—CO— in such a way that O atoms are not linked    directly to one another, and in which, in addition, one or more H    atoms may be replaced by halogen,-   Z¹ denotes a single bond, —CH₂CH₂—, —CH═CH—, —CH₂O—, —OCH₂—, —CF₂O—,    —OCF₂—, —COO—, —OCO—, —C₂F₄—, —CF═CF—, —CH═CHCHO—,-   L¹ and L² each, independently of one another, denote F, Cl, CF₃,    OCF₃ or CHF₂.

The mixtures according to the invention preferably exhibit very broadnematic phase ranges with clearing points ≧70° C., preferably ≧75° C.,in particular ≧80° C., very favourable values of the capacitivethreshold, relatively high values of the holding ratio and at the sametime very good low-temperature stabilities at −20° C. and −30° C., aswell as very low rotational viscosity values and short response times.The mixtures according to the invention are furthermore distinguished bythe fact that, in addition to the improvement in the rotationalviscosity γ₁, relatively high values of the elastic constants K₃₃ forimproving the response times can be observed. The compounds of theformula I are suitable, in particular, for the preparation of negativeΔ∈ mixtures which are intended to have a Δn>0.1.

Some preferred embodiments of the mixtures according to the inventionare indicated below.

In the compounds of the formula I, R¹ preferably denotes straight-chainalkyl, in particular CH₃, C₂H₅, n-C₃H₇, n-C₄H₉, nC₅H₁₁ and n-C₆H₁₃.

In the compounds of the formula I, R¹* preferably denotes straight-chainalkoxy, in particular OC₂H₅, OC₃H₇, OC₄H₉, OC₅H₁₁, OC₆H₁₃, furthermorealkenyloxy, in particular OCH₂CH═CH₂, OCH₂CH═CHCH₃, OCH₂CH═CHC₂H₅,furthermore alkyl, in particular n-C₃H₇, n-C₄H₉, n-C₅H₁₁, n-C₆H₁₃.

Preferred compounds of the formula I are the compounds of the formulaeI-1 to I-145,

in whichL¹ and L² each, independently of one another, denote F or Cl. In thecompounds of the formula I and in sub-formulae I-1 to I-145, preferablyL¹=L²=F. Z¹ preferably denotes a single bond.

Particular preference is given to the compounds of the formulae I-1,I-3, I-7, I-13, I-15, I-19, I-25 and I-26.

The mixture according to the invention very particularly preferablycomprises at least two compounds of the formula I-A:

The mixtures according to the invention very particularly preferablycomprise at least two compounds from the following group:

Preference is furthermore given to mixtures which comprise at leastthree compounds of the formula I. The mixtures according to theinvention preferably comprise the following three compounds:

The compounds of the formula I are, for example, from U.S. Pat. No.5,273,680 and can be prepared by known processes.

The media according to the invention preferably comprise two, three,four or more, preferably two or three, compounds of the formula I.

The compounds of the formula I are preferably employed in theliquid-crystalline medium in amounts of 5-65% by weight, preferably10-45% by weight, based on the mixture as a whole. Particular preferenceis given to liquid-crystalline media which comprise 25-45% by weight ofone or more, preferably two or three, compounds of the formula I.

Preferred embodiments of the liquid-crystalline medium according to theinvention are indicated below:

-   a) Liquid-crystalline medium which additionally comprises one or    more compounds selected from the group of the compounds of the    formulae IIA, IIB and IIC,

-   -   in which    -   R^(2A), R^(2B) and R^(2C) each, independently of one another,        denote H, an alkyl radical having up to 15 C atoms which is        unsubstituted, monosubstituted by CN or CF₃ or at least        monosubstituted by halogen, where, in addition, one or more CH₂        groups in these radicals may be replaced by —O—, —S—,

-   -    —C≡C—, —CF₂O—, —OCF₂—, —OC—O— or —O—CO— in such a way that O        atoms are not linked directly to one another,    -   L¹⁻⁴ each, independently of one another, denote F, Cl, CF₃ or        CHF₂,    -   Z² and Z^(2′) each, independently of one another, denote a        single bond, —CH₂CH₂—, —CH═CH—, —CF₂O—, —OCF₂—, —CH₂O—, —OCH₂—,        —COO—, —OCO—, —C₂F₄—, —CF═CF—, —CH═CHCH₂O—,    -   denotes 1 or 2,    -   q denotes 1 or 2, and    -   v denotes 1 to 6.    -   In the compounds of the formulae IIA and IIB, Z² may have        identical or different meanings. In the compounds of the formula        IIB, Z² and Z^(2′) may have identical or different meanings.    -   In the compounds of the formulae IIA, IIB and IIC, R^(2A),        R^(2B) and R^(2C) each preferably denote alkyl having 1-6 C        atoms, in particular CH₃, C₂H₅, n-C₃H₇, n-C₄H₉, n-C₅H₁₁.    -   In the compounds of the formulae IIA and IIB, L¹, L², L³ and L⁴        preferably denote L¹=L²=F and L³=L⁴=F, furthermore L¹=F and        L²=Cl, L¹=C¹ and L²=F, L³=F and L⁴=Cl, L³=C¹ and L⁴=F. Z² and        Z^(2′) in the formulae IIA and IIB preferably each,        independently of one another, denote a single bond, furthermore        a —C₂H₄— bridge. If in the formula IIB Z²=—C₂H₄—, Z^(2′) is        preferably a single bond or, if Z^(2′)=—C₂H₄—, Z² is preferably        a single bond. In the compounds of the formulae IIA and IIB,        (O)C_(v)H_(2v+1) preferably denotes OC_(v)H_(2v+1), furthermore        C_(v)H_(2v+1). In the compounds of the formula IIC,        (O)C_(v)H_(2v+1) preferably denotes C_(v)H_(2v+1). In the        compounds of the formula IIC, L³ and L⁴ preferably each denote        F.    -   Preferred compounds of the formulae IIA, IIB and IIC are        indicated below:

-   -   in which alkyl and alkyl* each, independently of one another,        denote a straight-chain alkyl radical having 1-6 C atoms.    -   Particularly preferred mixtures according to the invention        comprise one or more compounds of the formulae IIA-2, IIA-8,        IIA-14, IIA-29, IIA-35, IIB-2, IIB-12 and IIC-1.    -   The proportion of compounds of the formulae IIA and/or IIB in        the mixture as a whole is preferably at least 20% by weight.    -   Particularly preferred media according to the invention comprise        at least one compound of the formula IIC-1,

-   -   in which alkyl and alkyl* have the meanings indicated above,        preferably in amounts of >3% by weight, in particular >5% by        weight and particularly preferably 5-25% by weight.

-   b) Liquid-crystalline medium which additionally comprises one or    more compounds of the formula III,

-   -   in which    -   R³¹ and R³² each, independently of one another, denote a        straight-chain alkyl, alkoxyalkyl or alkoxy radical having up to        12 C atoms, and

-   -   denotes

-   -   Z³ denotes a single bond, —CH₂CH₂—, —CH═CH—, —CF₂O—, —OCF₂—,        —CH₂O—, —OCH₂—, —COO—, —OCO—, —C₂F₄—, —C₄H₈—, —CF═CF—.    -   Preferred compounds of the formula III are indicated below:

-   -   in which    -   alkyl and    -   alkyl* each, independently of one another, denote a        straight-chain alkyl radical having 1-6 C atoms.    -   The medium according to the invention preferably comprises at        least one compound of the formula IIIa and/or formula IIIb.    -   The proportion of compounds of the formula III in the mixture as        a whole is preferably at least 5% by weight.

-   c) Liquid-crystalline medium additionally comprising a compound of    the formula

-   -   preferably in total amounts of 5% by weight, in particular 10%        by weight.    -   Preference is furthermore given to mixtures according to the        invention comprising the compound

-   d) Liquid-crystalline medium which additionally comprises one or    more tetracyclic compounds of the formulae

-   -   in which    -   R⁷⁻¹⁰ each, independently of one another, have one of the        meanings indicated for R^(2A) in Claim 10, and    -   w and x each, independently of one another, denote 1 to 6.    -   Particular preference is given to mixtures comprising at least        one compound of the formula V-9.

-   e) Liquid-crystalline medium which additionally comprises one or    more compounds of the formulae Y-1 to Y-6,

-   -   in which R¹⁴-R¹⁹ each, independently of one another, denote an        alkyl or alkoxy radical having 1-6 C atoms; z and m each,        independently of one another, denote 1-6; x denotes 0, 1, 2 or        3.    -   The medium according to the invention particularly preferably        comprises one or more compounds of the formulae Y-1 to Y-6,        preferably in amounts of ≧5% by weight.

-   f) Liquid-crystalline medium additionally comprising one or more    fluorinated terphenyls of the formulae T-1 to T-21,

-   -   in which    -   R denotes a straight-chain alkyl or alkoxy radical having 1-7 C        atoms, and m=0, 1, 2, 3, 4, 5 or 6 and n denotes 0, 1, 2, 3 or        4.    -   R preferably denotes methyl, ethyl, propyl, butyl, pentyl,        hexyl, methoxy, ethoxy, propoxy, butoxy, pentoxy.    -   The medium according to the invention preferably comprises the        terphenyls of the formulae T-1 to T-21 in amounts of 2-30% by        weight, in particular 5-20% by weight.    -   Particular preference is given to compounds of the formulae T-1,        T-2, T-20 and T-21. In these compounds, R preferably denotes        alkyl, furthermore alkoxy, each having 1-5 C atoms. In the        compounds of the formula T-20, R preferably denotes alkyl or        alkenyl, in particular alkyl. In the compound of the formula        T-21, R preferably denotes alkyl.    -   The terphenyls are preferably employed in the mixtures according        to the invention if the Δn value of the mixture is to be ≧0.1.        Preferred mixtures comprise 2-20% by weight of one or more        terphenyl compounds selected from the group of the compounds T-1        to T-21.

-   g) Liquid-crystalline medium additionally comprising one or more    biphenyls of the formulae B-1 to B-3,

-   -   in which    -   alkyl and alkyl* each, independently of one another, denote a        straight-chain alkyl radical having 1-6 C atoms, preferably        having 3-5 C atoms, and    -   alkenyl and alkenyl* each, independently of one another, denote        a straight-chain alkenyl radical having 2-6 C atoms.    -   The proportion of the biphenyls of the formulae B-1 to B-3 in        the mixture as a whole is preferably at least 3% by weight, in        particular 5% by weight.

Of the compounds of the formulae B-1 to B-3, the compounds of theformula B-2 are particularly preferred.

-   -   Particularly preferred biphenyls are

-   -   in which alkyl* denotes an alkyl radical having 1-6 C atoms. The        medium according to the invention particularly preferably        comprises one or more compounds of the formulae B-1a and/or        B-2c.

-   h) Liquid-crystalline medium comprising at least one compound of the    formulae Z-1 to Z-7,

-   -   in which R and alkyl have the meanings indicated above.

-   i) Liquid-crystalline medium comprising at least one compound of the    formulae O-1 to O-17,

-   -   in which R¹ and R² have the meanings indicated for R^(2A). R¹        and R² preferably each, independently of one another, denote        straight-chain alkyl.    -   Preferred media comprise one or more compounds of the formulae        O-1, O-3, O-4, O-5, O-9, O-13, O-14, O-15, O-16 and/or O-17.

Mixtures according to the invention very particularly preferablycomprise one or more compound(s) of the formula O-9, O-15, O-16 and/orO-17, in particular in amounts of 5-30%.

Preferred compounds of the formulae O-15 and O-16 are indicated below:

-   -   The medium according to the invention particularly preferably        comprises the tricyclic compounds of the formula O-15a and/or of        the formula O-15b in combination with one or more bicyclic        compounds of the formulae O-16a to O-16d. The total proportion        of the compounds of the formulae O-15a and/or O-15b in        combination with one or more compounds selected from the        bicyclic compounds of the formulae O-16a to O-16d is 5-40%, very        particularly preferably 15-35%.

Very particularly preferred mixtures comprise compounds O-15a and O-16a:

-   -   Compounds O-15a and O-16a are preferably present in the mixture        in a concentration of 15-35%, particularly preferably 15-25% and        especially preferably 18-22%, based on the mixture as a whole.

Very particularly preferred mixtures comprise compounds O-15b and O-16a:

-   -   Compounds O-15b and O-16a are preferably present in the mixture        in a concentration of 15-35%, particularly preferably 15-25% and        especially preferably 18-22%, based on the mixture as a whole.    -   Very particularly preferred mixtures comprise the following        three compounds:

-   -   Compounds O-15a, O-15b and O-16a are preferably present in the        mixture in a concentration of 15-35%, particularly preferably        15-25% and especially preferably 18-22%, based on the mixture as        a whole.

-   j) Preferred liquid-crystalline media according to the invention    comprise one or more substances which contain a tetrahydronaphthyl    or naphthyl unit, such as, for example, the compounds of the    formulae N-1 to N-5,

-   -   in which R^(1N) and R^(2N) each, independently of one another,        have the meanings indicated for R^(2A), preferably denote        straight-chain alkyl, straight-chain alkoxy or straight-chain        alkenyl, and    -   Z¹ and Z² each, independently of one another,        -   denote —C₂H₄—, —CH═CH—, —(CH₂)₄—, —(CH₂)₃O—, —O(CH₂)₃—,            —CH═CHCH₂CH₂—, —CH₂CH₂CH═CH—, —CH₂O—, —OCH₂—, —COO—, —OCO—,            —C₂F₄—, —CF═CF—, —CF═CH—, —CH═CF—, —CF₂O—, —OCF₂—, —CH₂— or            a single bond.

-   k) Preferred mixtures comprise one or more compounds selected from    the group of the difluorodibenzochroman compounds of the formula BC,    chromans of the formula CR, fluorinated phenanthrenes of the    formulae PH-1 and PH-2, fluorinated dibenzofurans of the formula BF,

-   -   in which    -   R^(B1), R^(B2), R^(CR1), R^(CR2), R¹, R² each, independently of        one another, have the meaning of R^(2A). c is 0, 1 or 2.    -   The mixtures according to the invention preferably comprise the        compounds of the formulae BC, CR, PH-1, PH-2 and/or BF in        amounts of 3 to 20% by weight, in particular in amounts of 3 to        15% by weight.    -   Particularly preferred compounds of the formulae BC and CR are        the compounds BC-1 to BC-7 and CR-1 to CR-5,

-   -   in which    -   alkyl and alkyl* each, independently of one another, denote a        straight-chain alkyl radical having 1-6 C atoms, and    -   alkenyl and    -   alkenyl* each, independently of one another, denote a        straight-chain alkenyl radical having 2-6 C atoms.

Very particular preference is given to mixtures comprising one, two orthree compounds of the formula BC-2.

-   l) Preferred mixtures comprise one or more indane compounds of the    formula In,

-   -   in which    -   R¹¹, R¹²,    -   R¹³ each, independently of one another, denote a straight-chain        alkyl, alkoxy, alkoxyalkyl or alkenyl radical having 1-6 C        atoms,    -   R¹² and R¹³ additionally denote halogen, preferably F,

-   -   denotes

-   -   i denotes 0, 1 or 2.    -   Preferred compounds of the formula In are the compounds of the        formulae In-1 to In-16 indicated below:

-   -   Particular preference is given to the compounds of the formulae        In-1, In-2, In-3 and In-4.    -   The compounds of the formula In and the sub-formulae In-1 to        In-16 are preferably employed in the mixtures according to the        invention in concentrations ≧5% by weight, in particular 5-30%        by weight and very particularly preferably 5-25% by weight.

-   m) Preferred mixtures additionally comprise one or more compounds of    the formulae L-1 to L-11,

-   -   in which    -   R, R¹ and R² each, independently of one another, have the        meanings indicated for R^(2A) in Claim 10, and alkyl denotes an        alkyl radical having 1-6 C atoms. s denotes 1 or 2.

Particular preference is given to the compounds of the formulae L-1 andL-4, in particular L-4.

The compounds of the formulae L-1 to L-11 are preferably employed inconcentrations of 5-50% by weight, in particular 5-40% by weight andvery particularly preferably 10-40% by weight.

-   n) The medium additionally comprises one or more compounds of the    formula EY

-   -   in which R¹, R¹*, L¹ and L² have the meanings indicated in        formula I. In the compounds of the formula EY, R¹ and R¹*        preferably denote alkoxy having ≧2 C atoms, and L¹=L²=F.        Particular preference is given to the compounds of the formulae

-   -   The compound(s) of the formula EY are preferably employed in        amounts of 3-15% by weight, based on the mixture as a whole.

The mixtures according to the invention preferably comprise one or morecompounds of the formula P4

in which R¹ has the meaning indicated for formula I in Claim 1.

The compound of the formula P4 is preferably present in the mixtureaccording to the invention in concentrations of 0-5% by weight, inparticular in concentrations of 0-2% by weight.

Particularly preferred mixture concepts are indicated below: (Theacronyms used are explained in Table A. n and m here each, independentlyof one another, denote 1-6).

The mixtures according to the invention preferably comprise

-   -   one or more compounds of the formula I in which L¹=L²=F and        R¹=alkyl and R¹*=alkoxy;    -   CPY-n-Om, in particular CPY-2-O2, CPY-3-O2 and/or CPY-5-O2,        preferably in concentrations >5%, in particular 10-30%, based on        the mixture as a whole,        and/or    -   CY-n-Om, preferably CY-3-O2, CY-3-O4, CY-5-O2 and/or CY-5-O4,        preferably in concentrations >5%, in particular 15-50%, based on        the mixture as a whole,        and/or    -   CCY-n-Om, preferably CCY-2-O2, CCY-3-O1, CCY-3-O2, CCY-3-O3,        CCY-4-O2 and/or CCY-5-O2, preferably in concentrations >5%, in        particular 10-30%, based on the mixture as a whole,        and/or    -   CLY-n-Om, preferably CLY-2-O4, CLY-3-O2 and/or CLY-3-O3,        preferably in concentrations >5%, in particular 10-30%, based on        the mixture as a whole,        and/or    -   CK-n-F, preferably CK-3-F, CK-4-F and/or CK-5-F, preferably >5%,        in particular 5-25%, based on the mixture as a whole.

Preference is furthermore given to mixtures according to the inventionwhich comprise the following mixture concepts:

(n and m each, independently of one another, denote 1-6.)

-   -   CPY-n-Om and CY-n-Om, preferably in concentrations of 10-80%        based on the mixture as a whole,        and/or    -   CPY-n-Om and CK-n-F, preferably in concentrations of 10-70%        based on the mixture as a whole,        and/or    -   CPY-n-Om and CLY-n-Om, preferably in concentrations of 10-80%        based on the mixture as a whole,        and/or    -   Y-nO-Om, preferably in concentrations of 8-16%, based on the        mixture as a whole.

The invention furthermore relates to an electro-optical display havingactive-matrix addressing based on the ECB, VA, PS-VA, IPS, PS-IPS, FFSor PS-FFS effect, characterised in that it contains, as dielectric, aliquid-crystalline medium according to one or more of Claims 1 to 16.

The liquid-crystalline medium according to the invention preferably hasa nematic phase from ≦−20° C. to ≧70° C., particularly preferably from≦−30° C. to ≧80° C., very particularly preferably from ≦−40° C. to ≧90°C.

The expression “have a nematic phase” here means on the one hand that nosmectic phase and no crystallisation are observed at low temperatures atthe corresponding temperature and on the other hand that clearing stilldoes not occur on heating from the nematic phase. The investigation atlow temperatures is carried out in a flow viscometer at thecorresponding temperature and checked by storage in test cells having alayer thickness corresponding to the electro-optical use for at least100 hours. If the storage stability at a temperature of −20° C. in acorresponding test cell is 1000 h or more, the medium is referred to asstable at this temperature. At temperatures of −30° C. and −40° C., thecorresponding times are 500 h and 250 h respectively. At hightemperatures, the clearing point is measured by conventional methods incapillaries.

The liquid-crystal mixture preferably has a nematic phase range of atleast 60 K and a flow viscosity ν₂₀ of at most 30 mm²·s⁻¹ at 20° C.

The values of the birefringence Δn in the liquid-crystal mixture aregenerally between 0.07 and 0.16, preferably between 0.08 and 0.12.

The liquid-crystal mixture according to the invention has a Δ∈ of −0.5to −8.0, in particular −2.5 to −6.0, where Δ∈ denotes the dielectricanisotropy. The rotational viscosity γ₁ at 20° C. is preferably 165mPa·s, in particular 140 mPa·s.

The liquid-crystal media according to the invention have relatively lowvalues for the threshold voltage (V₀). They are preferably in the rangefrom 1.7 V to 3.0 V, particularly preferably 2.5 V and very particularlypreferably 2.3 V.

For the present invention, the term “threshold voltage” relates to thecapacitive threshold (V₀), also known as the Freedericks threshold,unless explicitly indicated otherwise.

In addition, the liquid-crystal media according to the invention havehigh values for the voltage holding ratio in liquid-crystal cells.

In general, liquid-crystal media having a low addressing voltage orthreshold voltage exhibit a lower voltage holding ratio than thosehaving a higher addressing voltage or threshold voltage and vice versa.

For the present invention, the term “dielectrically positive compounds”denotes compounds having a Δ∈>1.5, the term “dielectrically neutralcompounds” denotes those having −1.5≦Δ∈≦1.5 and the term “dielectricallynegative compounds” denotes those having Δ∈<−1.5. The dielectricanisotropy of the compounds is determined here by dissolving 10% of thecompounds in a liquid-crystalline host and determining the capacitanceof the resultant mixture in at least one test cell in each case having alayer thickness of 20 μm with homeotropic and with homogeneous surfacealignment at 1 kHz. The measurement voltage is typically 0.5 V to 1.0 V,but is always lower than the capacitive threshold of the respectiveliquid-crystal mixture investigated.

All temperature values indicated for the present invention are in ° C.

The mixtures according to the invention are suitable for all VA-TFTapplications, such as, for example, VAN, MVA, (S)-PVA, ASV, PSA (polymersustained VA) and PS-VA (polymer stabilized VA). They are furthermoresuitable for IPS (in-plane switching) and FFS (fringe field switching)applications having negative Δ∈.

The nematic liquid-crystal mixtures in the displays according to theinvention generally comprise two components A and B, which themselvesconsist of one or more individual compounds.

Component A has significantly negative dielectric anisotropy and givesthe nematic phase a dielectric anisotropy of ≦−0.5. Besides one or morecompounds of the formula I, it preferably comprises the compounds of theformulae IIA, IIB and/or IIC, furthermore compounds of the formula III.

The proportion of component A is preferably between 45 and 100%, inparticular between 60 and 100%.

For component A, one (or more) individual compound(s) which has (have) avalue of Δ∈≦−0.8 is (are) preferably selected. This value must be morenegative, the smaller the proportion A in the mixture as a whole.

Component B has pronounced nematogeneity and a flow viscosity of notgreater than 30 mm²·s⁻¹, preferably not greater than 25 mm²·s⁻¹, at 20°C.

Particularly preferred individual compounds in component B are extremelylow-viscosity nematic liquid crystals having a flow viscosity of notgreater than 18 mm²·s⁻¹, preferably not greater than 12 mm²·s⁻¹, at 20°C.

Component B is monotropically or enantiotropically nematic, has nosmectic phases and is able to prevent the occurrence of smectic phasesdown to very low temperatures in liquid-crystal mixtures. For example,if various materials of high nematogeneity are added to a smecticliquid-crystal mixture, the nematogeneity of these materials can becompared through the degree of suppression of smectic phases that isachieved.

The mixture may optionally also comprise a component C, comprisingcompounds having a dielectric anisotropy of Δ∈≧1.5. These so-calledpositive compounds are generally present in a mixture of negativedielectric anisotropy in amounts of ≦20% by weight, based on the mixtureas a whole.

A multiplicity of suitable materials is known to the person skilled inthe art from the literature. Particular preference is given to compoundsof the formula III.

In addition, these liquid-crystal phases may also comprise more than 18components, preferably 18 to 25 components.

Besides one or more compounds of the formula I, the phases preferablycomprise 4 to 15, in particular 5 to 12, and particularly preferably<10, compounds of the formulae IIA, IIB and/or IIC and optionally III.

Besides compounds of the formula I and the compounds of the formulaeIIA, IIB and/or IIC and optionally III, other constituents may also bepresent, for example in an amount of up to 45% of the mixture as awhole, but preferably up to 35%, in particular up to 10%.

The other constituents are preferably selected from nematic ornematogenic substances, in particular known substances, from the classesof the azoxybenzenes, benzylideneanilines, biphenyls, terphenyls, phenylor cyclohexyl benzoates, phenyl or cyclohexyl cyclohexanecarboxylates,phenylcyclohexanes, cyclohexylbiphenyls, cyclohexylcyclohexanes,cyclohexylnaphthalenes, 1,4-biscyclohexylbiphenyls orcyclohexylpyrimidines, phenyl- or cyclohexyldioxanes, optionallyhalogenated stilbenes, benzyl phenyl ethers, tolans and substitutedcinnamic acid esters.

The most important compounds which are suitable as constituents ofliquid-crystal phases of this type can be characterised by the formulaIV

R²⁰-L-G-E-R²¹  IV

in which L and E each denote a carbo- or heterocyclic ring system fromthe group formed by 1,4-disubstituted benzene and cyclohexane rings,4,4′-disubstituted biphenyl, phenylcyclohexane and cyclohexylcyclohexanesystems, 2,5-disubstituted pyrimidine and 1,3-dioxane rings,2,6-disubstituted naphthalene, di- and tetrahydronaphthalene,quinazoline and tetrahydroquinazoline,G denotes

-   -   —CH═CH— —N(O)=N—    -   —CH═CQ- —CH═N(O)—    -   —C≡C— —CH₂—CH₂—    -   —CO—O— —CH₂—O—    -   —CO—S— —CH₂—S—    -   —CH═N— —COO-Phe-COO—    -   —CF₂O— —CF═CF—    -   —OCF₂— —OCH₂—    -   —(CH₂)₄— —(CH₂)₃O—        or a C—C single bond, Q denotes halogen, preferably chlorine, or        —CN, and R²⁰ and R²¹ each denote alkyl, alkenyl, alkoxy,        alkoxyalkyl or alkoxycarbonyloxy having up to 18, preferably up        to 8, carbon atoms, or one of these radicals alternatively        denotes CN, NC, NO₂, NCS, CF₃, SF₅, OCF₃, F, Cl or Br.

In most of these compounds, R²⁰ and R²¹ are different from one another,one of these radicals usually being an alkyl or alkoxy group. Othervariants of the proposed substituents are also common. Many suchsubstances or also mixtures thereof are commercially available. Allthese substances can be prepared by methods known from the literature.

It goes without saying for the person skilled in the art that the VA,IPS or FFS mixture according to the invention may also comprisecompounds in which, for example, H, N, O, Cl and F have been replaced bythe corresponding isotopes.

Polymerisable compounds, so-called reactive mesogens (RMs), for exampleas disclosed in U.S. Pat. No. 6,861,107, may furthermore be added to themixtures according to the invention in concentrations of preferably0.12-5% by weight, particularly preferably 0.2-2% by weight, based onthe mixture. These mixtures may optionally also comprise an initiator,as described, for example, in U.S. Pat. No. 6,781,665. The initiator,for example Irganox-1076 from BASF, is preferably added to the mixturecomprising polymerisable compounds in amounts of 0-1%. Mixtures of thistype can be used for so-called polymer-stabilised VA modes (PS-VA) orPSA (polymer sustained VA), in which polymerisation of the reactivemesogens is intended to take place in the liquid-crystalline mixture.The prerequisite for this is that the liquid-crystal mixture does notitself comprise any polymerisable components.

In a preferred embodiment of the invention, the polymerisable compoundsare selected from the compounds of the formula M

R^(a)-A¹-(Z¹-A²)_(m)-R^(b)  M

in which the individual radicals have the following meanings:

-   R^(a) and R^(b) each, independently of one another, denote P, P-Sp-,    H, halogen, SF₅, NO₂, a carbon group or hydrocarbon group, where at    least one of the radicals R^(a) and R^(b) denotes or contains a    group P or P-Sp-,-   P on each occurrence, identically or differently, denotes a    polymerisable group,-   Sp on each occurrence, identically or differently, denotes a spacer    group or a single bond,-   A¹ and A² each, independently of one another, denote an aromatic,    heteroaromatic, alicyclic or heterocyclic group, preferably having 4    to 25 ring atoms, which may also contain fused rings, and which may    also be mono- or polysubstituted by L,-   L denotes P-Sp-, H, OH, CH₂OH, halogen, SF₅, NO₂, a carbon group or    hydrocarbon group,-   Z¹ on each occurrence, identically or differently,    -   denotes —O—, —S—, —CO—, —CO—O—, —OCO—, —O—CO—O—, —OCH₂—, —CH₂O—,        —SCH₂—, —CH₂S—, —CF₂O—, —OCF₂—, —CF₂S—, —SCF₂—, —(CH₂)_(n1)—,        —CF₂CH₂—, —CH₂CF₂—, —(CF₂)_(n1)—, —CH═CH—, —CF═CF—, —C≡C—,        —CH═CH—COO—, —OCO—CH═CH—, CR⁰R⁰⁰ or a single bond,-   R⁰ and R⁰⁰ each, independently of one another, denote H or alkyl    having 1 to 12 C atoms,-   m denotes 0, 1, 2, 3 or 4,-   n1 denotes 1, 2, 3 or 4.

Particularly preferred compounds of the formula M are those in which

-   R^(a) and R^(b) each, independently of one another, denote P, P-Sp-,    H, F, Cl, Br, I, —CN, —NO₂, —NCO, —NCS, —OCN, —SCN, SF₅ or    straight-chain or branched alkyl having 1 to 25 C atoms, in which,    in addition, one or more non-adjacent CH₂ groups may each be    replaced, independently of one another, by —C(R⁰)═C(R⁰⁰)—, —C≡C—,    —N(R⁰⁰)—, —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O— in such a way    that O and/or S atoms are not linked directly to one another, and in    which, in addition, one or more H atoms may be replaced by F, Cl,    Br, I, CN, P or P-Sp-, where at least one of the radicals R^(a) and    R^(b) denotes or contains a group P or P-Sp-,-   A¹ and A² each, independently of one another, denote 1,4-phenylene,    naphthalene-1,4-diyl, naphthalene-2,6-diyl, phenanthrene-2,7-diyl,    anthracene-2,7-diyl, fluorene-2,7-diyl, 2-oxo-2H-chromene-3,6-diyl,    2-oxo-2H-chromene-3,7-diyl, 4-oxo-4H-chromene-2,6-diyl,    4-oxo-4H-chromene-3,6-diyl, 4-oxo-4H-chromene-3,7-diyl (trivial name    coumarine or flavone), where, in addition, one or more CH groups in    these groups may be replaced by N, cyclohexane-1,4-diyl, in which,    in addition, one or more non-adjacent CH₂ groups may be replaced by    O and/or S, 1,4-cyclohexenylene, bicycle[1.1.1]pentane-1,3-diyl,    bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl,    piperidine-1,4-diyl, decahydronaphthalene-2,6-diyl,    1,2,3,4-tetrahydronaphthalene-2,6-diyl, indane-2,5-diyl or    octahydro-4,7-methanoindane-2,5-diyl, where all these groups may be    unsubstituted or mono- or polysubstituted by L,-   L denotes P, P-Sp-, OH, CH₂OH, F, Cl, Br, I, —CN, —NO₂, —NCO, —NCS,    —OCN, —SCN, —C(═O)N(R^(x))₂, —C(═O)Y¹, —C(═O)R^(x), —N(R^(x))₂,    optionally substituted silyl, optionally substituted aryl having 6    to 20 C atoms, or straight-chain or branched alkyl, alkoxy,    alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy    having 1 to 25 C atoms, in which, in addition, one or more H atoms    may be replaced by F, Cl, P or P-Sp-,-   P denotes a polymerisable group,-   Y¹ denotes halogen,-   R^(x) denotes P, P-Sp-, H, halogen, straight-chain, branched or    cyclic alkyl having 1 to 25 C atoms, in which, in addition, one or    more non-adjacent CH₂ groups may be replaced by —O—, —S—, —CO—,    —CO—O—, —O—CO—, —O—CO—O— in such a way that O and/or S atoms are not    linked directly to one another, and in which, in addition, one or    more H atoms may be replaced by F, Cl, P or P-Sp-, an optionally    substituted aryl or aryloxy group having 6 to 40 C atoms, or an    optionally substituted heteroaryl or heteroaryloxy group having 2 to    40 C atoms.

Further preferred compounds of the formula M are those selected from oneor more of the following sub-groups:

-   -   m is 2 or 3,    -   m is 2,    -   R^(a) and R^(b) denote identical or different groups P-Sp-,    -   R^(a) and R^(b) denote identical or different groups P-Sp- in        which one or more groups Sp denote a single bond,    -   m is 2 or 3, and R^(a) and R^(b) denote identical groups P-Sp-,    -   one of the radicals R^(a) and R^(b) denotes P-Sp- and the other        denotes an unpolymerisable group, preferably straight-chain or        branched alkyl having 1 to 25 C atoms, in which, in addition,        one or more non-adjacent CH₂ groups may each be replaced,        independently of one another, by —C(R⁰⁰)═C(R⁰⁰⁰)—, —C≡C—,        —N(R⁰⁰)—, —O—, —S—, —CO—, —CO—O—, —O—CO— or —O—CO—O— in such a        way that O and/or S atoms are not linked directly to one        another, and in which, in addition, one or more H atoms may be        replaced by F, Cl, Br, I or CN,    -   one or more groups Sp denote a single bond,    -   one or more groups Sp denote —(CH₂)_(p1)—, —(CH₂)_(p1)—O—,        —(CH₂)_(p1)—OCO— or —(CH₂)_(p1)—OCOO—, in which p1 denotes an        integer from 1 to 12, and r1 denotes an integer from 1 to 8,    -   L does not denote and/or contain a polymerisable group,    -   A¹ and A² denote, independently of one another, 1,4-phenylene or        naphthalene-2,6-diyl, in which, in addition, one or more CH        groups in these groups may be replaced by N and which may, in        addition, be mono- or polyfluorinated,    -   Z¹ is selected from the group consisting of —O—, —CO—O—, —OCO—,        —OCH₂—, —CH₂O—, —CF₂O—, —OCF₂—, —CH₂CH₂—, —CH═CH—, —CF═CF—,        —CH═CF—, —CF═CH—, —C≡C— and a single bond,    -   L is an unpolymerisable group, preferably selected from the        group consisting of F, Cl, —CN, straight-chain and branched        alkyl having 1 to 25 C atoms, in which, in addition, one or more        non-adjacent CH₂ groups may each be replaced, independently of        one another, by —C(R⁰⁰)═C(R⁰⁰⁰)—, —C≡C—, —N(R⁰⁰)—, —O—, —S—,        —CO—, —CO—, —CO—O—, —O—CO— or —O—CO—O— in such a way that O        and/or S atoms are not linked directly to one another, and in        which, in addition, one or more H atoms may be replaced by F,        Cl, Br, I or CN.

Suitable and preferred co-monomers for the production of LC mixturesaccording to the invention for the use in PS-VA, PS-IPS and PS-FFSapplications are selected, for example from the following formulae:

in which the individual radicals have the following meanings:

-   P¹, P² and P² each, identically or differently, denotes a    polymerisable group, preferably having one of the meanings indicated    above and below for P, particularly preferably an acrylate,    methacrylate, fluoroacrylate, oxetane, vinyloxy or epoxy group,-   Sp¹, Sp² and Sp³ each, independently of one another, denote a single    bond or a spacer group, preferably having one of the meanings    indicated above and below for Sp^(a), and particularly preferably    —(CH₂)_(p1)—, —(CH₂)_(p1)—O—, —(CH₂)_(p1)—CO—O— or    —(CH₂)_(p1)—O—CO—O—, in which p1 is an integer from 1 to 12, and    where in the last-mentioned groups the linking to the adjacent ring    takes place via the O atom, where one or more of the radicals    P¹-Sp¹-, P²-Sp²- and P³-Sp³- may also denote R^(aa), with the    proviso that at least one of the radicals P¹-Sp¹-, P²-Sp²- and    P³-Sp³- present does not denote R^(aa),-   R^(aa) denotes H, F, Cl, CN or straight-chain or branched alkyl    having 1 to 25 C atoms, in which, in addition, one or more    non-adjacent CH₂ groups may each be replaced, independently of one    another, by C(R⁰)═C(R⁰⁰)—, —C≡C—, —N(R⁰)—, —O—, —S—, —CO—, —CO—O—,    —O—CO—, —O—CO—O— in such a way that O and/or S atoms are not linked    directly to one another, and in which, in addition, one or more H    atoms may be replaced by F, Cl, CN or P¹-Sp¹-, particularly    preferably straight-chain or branched, optionally mono- or    polyfluorinated, alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl,    alkoxycarbonyl or alkylcarbonyloxy having 1 to 12 C atoms (where the    alkenyl and alkynyl radicals have at least two and the branched    radicals at least three C atoms),-   R⁰, R⁰⁰ each, independently of one another and on each occurrence    identically or differently, denote H or alkyl having 1 to 12 C    atoms,-   R^(y) and R^(z) each, independently of one another, denote H, F, CH₃    or CF₃,-   X¹, X² and X³ each, independently of one another, denote —CO—O—,    —O—CO— or a single bond,-   Z¹ denotes —O—, —CO—, —C(R^(y)R^(z))— or —CF₂CF₂—,-   Z² and Z³ each, independently of one another, denote —CO—O—, —O—CO—,    —CH₂O—, —OCH₂—, —CF₂O—, —OCF₂— or —(CH₂)_(n)—, where n is 2, 3 or 4,-   L on each occurrence, identically or differently, denotes F, Cl, CN,    SON, SF₅ or straight-chain or branched, optionally mono- or    polyfluorinated, alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl,    alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12    C atoms, preferably F,-   L′ and L″ each, independently of one another, denote H, F or Cl,-   r denotes 0, 1, 2, 3 or 4,-   s denotes 0, 1, 2 or 3,-   t denotes 0, 1 or 2,-   x denotes 0 or 1.

In a preferred embodiment, in the compounds of the formula M1 to M34

denotes

in which L on each occurrence, identically or differently, has one ofthe meanings indicated and in particular denotes F, Cl, CN, NO₂, CH₃,C₂H₅, C(CH₃)₃, CH(CH₃)₂, CH₂CH(CH₃)C₂H₅, OCH₃, OC₂H₅, COCH₃, COC₂H₅,COOCH₃, COOC₂H₅, CF₃, OCF₃, OCHF₂, OC₂F₅ oder P-Sp-, preferably F, Cl,CN, CH₃, C₂H₅, OCH₃, COCH₃, OCF₃ or P-Sp-, most preferably F, Cl, CH₃,OCH₃, COCH₃ or OCF₃, in particular F or CH₃.

In a further preferred embodiment of the invention, the polymerisablecompounds are chiral or optically active compounds selected from formulaII* (chiral RMs):

(R*-(A¹-Z¹)_(m))_(k)-Q  II*

in which A¹, Z¹ and m have on each occurrence, identically ordifferently, one of the meanings indicated in formula M,

-   R* has on each occurrence, identically or differently, one of the    meanings indicated for R^(a) in formula M, where R* can be chiral or    achiral,-   Q denotes a k-valent chiral group, which is optionally mono- or    polysubstituted by L, as defined in formula M,-   k is 1, 2, 3, 4, 5 or 6,-   where the compounds contain at least one radical R* or L which    denotes or contains a group P or P-Sp- as defined above.

Particularly preferred compounds of the formula II* contain a monovalentgroup Q of the formula III*

in which L and r have on each occurrence, identically or differently,the meanings indicated above,

-   A* and B* each, independently of one another, denote fused benzene,    cyclohexane or cyclohexene,-   t on each occurrence, identically or differently, denotes 0, 1 or 2,    and-   u on each occurrence, identically or differently, denotes 0, 1 or 2.

Particular preference is given to groups of the formula III* in which udenotes 1.

Further preferred compounds of the formula II* contain a monovalentgroup Q or one or more groups R* of the formula IV*

in which

-   Q¹ denotes alkylene or alkyleneoxy having 1 to 9 C atoms or a single    bond,-   Q² denotes optionally fluorinated alkyl or alkoxy having 1 to 10 C    atoms, in which, in addition, one or two non-adjacent CH₂ groups may    be replaced by —O—, —S—, —CH═CH—, —CO—, —OCO—, —COO—, —O—COO—,    —S—CO—, —CO—S— or —C≡C— in such a way that O and/or S atoms are not    linked directly to one another,-   Q³ denotes F, Cl, CN or alkyl or alkoxy as defined for Q², but    different from Q².

Preferred groups of the formula IV* are, for example, 2-butyl(=1-methylpropyl), 2-methylbutyl, 2-methylpentyl, 3-methylpentyl,2-ethylhexyl, 2-propylpentyl, in particular 2-methylbutyl,2-methylbutoxy, 2-methylpentoxy, 3-methylpentoxy, 2-ethylhexoxy,1-methylhexoxy, 2-octyloxy, 2-oxa-3-methylbutyl, 3-oxa-4-methylpentyl,4-methylhexyl, 2-hexyl, 2-octyl, 2-nonyl, 2-decyl, 2-dodecyl,6-methoxyoctoxy, 6-methyloctoxy, 6-methyloctanoyloxy,5-methylheptyloxycarbonyl, 2-methylbutyryloxy, 3-methylvaleroyloxy,4-methylhexanoyloxy, 2-chloropropionyloxy, 2-chloro-3-methylbutyryloxy,2-chloro-4-methylvaleryloxy, 2-chloro-3-methylvaleryloxy,2-methyl-3-oxapentyl, 2-methyl-3-oxahexyl, 1-methoxypropyl-2-oxy,1-ethoxypropyl-2-oxy, 1-propoxypropyl-2-oxy, 1-butoxypropyl-2-oxy,2-fluorooctyloxy, 2-fluorodecyloxy, 1,1,1-trifluoro-2-octyloxy,1,1,1-trifluoro-2-octyl, 2-fluoromethyloctyloxy.

Further preferred compounds of the formula II* contain a divalent groupQ of the formula V*

in which L, r, t, A* and B* have the meanings indicated above.

Further preferred compounds of the formula II* contain a divalent groupQ selected from the following formulae:

in which Phe denotes phenyl, which is optionally mono- orpolysubstituted by L, and R^(x) denotes F or optionally fluorinatedalkyl having 1 to 4 C atoms.

Suitable chiral RMs are described, for example, in GB 2 314 839 A, U.S.Pat. No. 6,511,719, U.S. Pat. No. 7,223,450, WO 02/34739 A1, U.S. Pat.No. 7,041,345, U.S. Pat. No. 7,060,331 or U.S. Pat. No. 7,318,950.Suitable RMs containing binaphthyl groups are described, for example, inU.S. Pat. No. 6,818,261, U.S. Pat. No. 6,916,940, U.S. Pat. No.7,318,950 and U.S. Pat. No. 7,223,450.

The chiral structural elements shown above and below and polymerisableand polymerised compounds containing such chiral structural elements canbe employed in optically active form, i.e. as pure enantiomers or as anydesired mixture of the two enantiomers, or alternatively as a racemate.The use of racemates is preferred. The use of racemates has someadvantages over the use of pure enantiomers, such as, for example,significantly lower synthesis complexity and lower material costs.

The compounds of the formula II* are preferably present in the LC mediumin the form of the racemate.

Particularly preferred compounds of the formula II* are selected fromthe following sub-formulae:

in which L, P, Sp, m, r and t have the meanings indicated above, Z and Ahave on each occurrence, identically or differently, one of the meaningsindicated for Z¹ and A¹ respectively, and t1 on each occurrence,identically or differently, denotes 0 or 1.

The term “carbon group” denotes a mono- or polyvalent organic groupcontaining at least one carbon atom, where this either contains nofurther atoms (such as, for example, —C≡C—) or optionally contains oneor more further atoms, such as, for example, N, O, S, P, Si, Se, As, Teor Ge (for example carbonyl, etc.). The term “hydrocarbon group” denotesa carbon group which additionally contains one or more H atoms andoptionally one or more heteroatoms, such as, for example, N, O, S, P,Si, Se, As, Te or Ge.

“Halogen” denotes F, Cl, Br or I.

A carbon or hydrocarbon group can be a saturated or unsaturated group.Unsaturated groups are, for example, aryl, alkenyl or alkynyl groups. Acarbon or hydrocarbon radical having more than 3 C atoms can bestraight-chain, branched and/or cyclic and may also contain spiro linksor condensed rings.

The terms “alkyl”, “aryl”, “heteroaryl”, etc., also encompass polyvalentgroups, for example alkylene, arylene, heteroarylene, etc.

The term “aryl” denotes an aromatic carbon group or a group derivedtherefrom. The term “heteroaryl” denotes “aryl” as defined above,containing one or more heteroatoms.

Preferred carbon and hydrocarbon groups are optionally substitutedalkyl, alkenyl, alkynyl, alkoxy, alkylcarbonyl, alkoxycarbonyl,alkylcarbonyloxy and alkoxycarbonyloxy having 1 to 40, preferably 1 to25, particularly preferably 1 to 18, C atoms, optionally substitutedaryl or aryloxy having 6 to 40, preferably 6 to 25, C atoms, oroptionally substituted alkylaryl, arylalkyl, alkylaryloxy, arylalkyloxy,arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryloxycarbonyloxyhaving 6 to 40, preferably 6 to 25, C atoms.

Further preferred carbon and hydrocarbon groups are C₁-C₄₀ alkyl, C₂-C₄₀alkenyl, C₂-C₄₀ alkynyl, C₃-C₄₀ allyl, C₄-C₄₀ alkyldienyl, C₄-C₄₀polyenyl, C₆-C₄₀ aryl, C₆-C₄₀ alkylaryl, C₆-C₄₀ arylalkyl, C₆-C₄₀alkylaryloxy, C₆-C₄₀ arylalkyloxy, C₂-C₄₀ heteroaryl, C₄-C₄₀ cycloalkyl,C₄-C₄₀ cycloalkenyl, etc. Particular preference is given to C₁-C₂₂alkyl, C₂-C₂₂ alkenyl, C₂-C₂₂ alkynyl, C₃-C₂₂ allyl, C₄-C₂₂ alkyldienyl,C₆-C₁₂ aryl, C₆-C₂₀ arylalkyl and C₂-C₂₀ heteroaryl.

Further preferred carbon and hydrocarbon groups are straight-chain,branched or cyclic alkyl radicals having 1 to 40, preferably 1 to 25, Catoms, which are unsubstituted or mono- or polysubstituted by F, Cl, Br,I or CN and in which one or more non-adjacent CH₂ groups may each bereplaced, independently of one another,

by —C(R^(x))═C(R^(x))—, —C≡C—, —N(R^(x))—, —O—, —S—, —CO—, —CO—O—,—O—CO—, —O—CO—O— in such a way that O and/or S atoms are not linkeddirectly to one another.

R^(x) preferably denotes H, halogen, a straight-chain, branched orcyclic alkyl chain having 1 to 25 C atoms, in which, in addition, one ormore non-adjacent C atoms may be replaced by —O—, —S—, —CO—, —CO—O—,—O—CO—, —O—CO—O— and in which one or more H atoms may be replaced byfluorine, an optionally substituted aryl or aryloxy group having 6 to 40C atoms, or an optionally substituted heteroaryl or heteroaryloxy grouphaving 2 to 40 C atoms.

Preferred alkoxy groups are, for example, methoxy, ethoxy,2-methoxyethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy,t-butoxy, 2-methylbutoxy, n-pentoxy, n-hexoxy, n-heptoxy, n-octoxy,n-nonoxy, n-decoxy, n-undecoxy, n-dodecoxy, etc.

Preferred alkyl groups are, for example, methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl,s-pentyl, cyclopentyl, n-hexyl, cyclohexyl, 2-ethylhexyl, n-heptyl,cycloheptyl, n-octyl, cyclooctyl, n-nonyl, n-decyl, n-undecyl,n-dodecyl, dodecanyl, trifluoromethyl, perfluoro-n-butyl,2,2,2-trifluoroethyl, perfluorooctyl, perfluorohexyl, etc.

Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl,pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl,octenyl, cyclooctenyl, etc.

Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl,pentynyl, hexynyl, octynyl, etc.

Preferred alkoxy groups are, for example, methoxy, ethoxy,2-methoxyethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy,t-butoxy, 2-methylbutoxy, n-pentoxy, n-hexoxy, n-heptoxy, n-octoxy,n-nonoxy, n-decoxy, n-undecoxy, n-dodecoxy, etc.

Preferred amino groups are, for example, dimethylamino, methylamino,methylphenylamino, phenylamino, etc.

Aryl and heteroaryl groups can be monocyclic or polycyclic, i.e. theycan contain one ring (such as, for example, phenyl) or two or morerings, which may also be fused (such as, for example, naphthyl) orcovalently bonded (such as, for example, biphenyl), or contain acombination of fused and linked rings. Heteroaryl groups contain one ormore heteroatoms, preferably selected from O, N, S and Se.

Particular preference is given to mono-, bi- or tricyclic aryl groupshaving 6 to 25 C atoms and mono-, bi- or tricyclic heteroaryl groupshaving 2 to 25 C atoms, which optionally contain fused rings and areoptionally substituted. Preference is furthermore given to 5-, 6- or7-membered aryl and heteroaryl groups, in which, in addition, one ormore CH groups may be replaced by N, S or O in such a way that O atomsand/or S atoms are not linked directly to one another.

Preferred aryl groups are, for example, phenyl, biphenyl, terphenyl,1,1′:3′,1″-terphenyl-2′-yl, naphthyl, anthracene, binaphthyl,phenanthrene, pyrene, dihydropyrene, chrysene, perylene, tetracene,pentacene, benzopyrene, fluorene, indene, indenofluorene,spirobifluorene, etc.

Preferred heteroaryl groups are, for example, 5-membered rings, such aspyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole,furan, thiophene, selenophene, oxazole, isoxazole, 1,2-thiazole,1,3-thiazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole,1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole,1,2,5-thiadiazole, 1,3,4-thiadiazole, 6-membered rings, such aspyridine, pyridazine, pyrimidine, pyrazine, 1,3,5-triazine,1,2,4-triazine, 1,2,3-triazine, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine,1,2,3,5-tetrazine, or condensed groups, such as indole, isoindole,indolizine, indazole, benzimidazole, benzotriazole, purine,naphthimidazole, phenanthrimidazole, pyridimidazole, pyrazinimidazole,quinoxalinimidazole, benzoxazole, naphthoxazole, anthroxazole,phenanthroxazole, isoxazole, benzothiazole, benzofuran, isobenzofuran,dibenzofuran, quinoline, isoquinoline, pteridine, benzo-5,6-quinoline,benzo-6,7-quinoline, benzo-7,8-quinoline, benzoisoquinoline, acridine,phenothiazine, phenoxazine, benzopyridazine, benzopyrimidine,quinoxaline, phenazine, naphthyridine, azacarbazole, benzocarboline,phenanthridine, phenanthroline, thieno[2,3b]thiophene,thieno[3,2b]thiophene, dithienothiophene, isobenzothiophene,dibenzothiophene, benzothiadiazothiophene, or combinations of thesegroups. The heteroaryl groups may also be substituted by alkyl, alkoxy,thioalkyl, fluorine, fluoroalkyl or further aryl or heteroaryl groups.

The (non-aromatic) alicyclic and heterocyclic groups encompass bothsaturated rings, i.e. those containing exclusively single bonds, andalso partially unsaturated rings, i.e. those which may also containmultiple bonds. Heterocyclic rings contain one or more heteroatoms,preferably selected from Si, O, N, S and Se.

The (non-aromatic) alicyclic and heterocyclic groups can be monocyclic,i.e. contain only one ring (such as, for example, cyclohexane), orpolycyclic, i.e. contain a plurality of rings (such as, for example,decahydronaphthalene or bicyclooctane). Particular preference is givento saturated groups. Preference is furthermore given to mono-, bi- ortricyclic groups having 3 to 25 C atoms, which optionally contain fusedrings and are optionally substituted. Preference is furthermore given to5-, 6-, 7- or 8-membered carbocyclic groups, in which, in addition, oneor more C atoms may be replaced by Si and/or one or more CH groups maybe replaced by N and/or one or more non-adjacent CH₂ groups may bereplaced by —O— and/or —S—.

Preferred alicyclic and heterocyclic groups are, for example, 5-memberedgroups, such as cyclopentane, tetrahydrofuran, tetrahydrothiofuran,pyrrolidine, 6-membered groups, such as cyclohexane, silinane,cyclohexene, tetrahydropyran, tetrahydrothiopyran, 1,3-dioxane,1,3-dithiane, piperidine, 7-membered groups, such as cycloheptane, andfused groups, such as tetrahydronaphthalene, decahydronaphthalene,indane, bicyclo[1.1.1]-pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl,spiro[3.3]heptane-2,6-diyl, octahydro-4,7-methanoindane-2,5-diyl.

Preferred substituents are, for example, solubility-promoting groups,such as alkyl or alkoxy, electron-withdrawing groups, such as fluorine,nitro or nitrile, or substituents for increasing the glass transitiontemperature (Tg) in the polymer, in particular bulky groups, such as,for example, t-butyl or optionally substituted aryl groups.

Preferred substituents, also referred to as “L” above and below, are,for example, F, Cl, Br,

I, —CN, —NO₂, —NCO, —NCS, —OCN, —SCN, —C(═O)N(R^(x))₂, —C(═O)Y¹,—C(═O)R^(x), —N(R^(x))₂, in which R^(x) has the meaning indicated above,and Y¹ denotes halogen, optionally substituted silyl or aryl having 6 to40, preferably 6 to 20, C atoms, and straight-chain or branched alkyl,alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy oralkoxycarbonyloxy having 1 to 25 C atoms, in which one or more H atomsmay optionally be replaced by F or Cl.

“Substituted silyl or aryl” preferably means substituted by halogen,—CN, R⁰, —OR⁰, —CO—R⁰, —CO—O—R⁰, —O—CO—R⁰ or —O—CO—O—R⁰, in which R⁰ hasthe meaning indicated above.

Particularly preferred substituents L are, for example, F, Cl, CN, NO₂,CH₃, C₂H₅, OCH₃, OC₂H₅, COCH₃, COC₂H₅, COOCH₃, COOC₂H₅, CF₃, OCF₃,OCHF₂, OC₂F₅, furthermore phenyl.

is preferably

in which L has one of the meanings indicated above.

The polymerisable group P is a group which is suitable for apolymerisation reaction, such as, for example, free-radical or ionicchain polymerisation, polyaddition or polycondensation, or for apolymer-analogous reaction, for example addition or condensation onto amain polymer chain. Particular preference is given to groups for chainpolymerisation, in particular those containing a C═C double bond or—C≡C— triple bond, and groups which are suitable for polymerisation withring opening, such as, for example, oxetane or epoxide groups.

Preferred groups P are selected from CH₂═CW¹—COO—, CH₂═CW¹—CO—,

CH₂═CW²—(O)_(k3)—, CW¹═CH—CO—(O)_(k3)—, CW¹═CH—CO—NH—, CH₂═CW¹—CO—NH—,CH₃—CH═CH—O—, (CH₂═CH)₂CH—OCO—, (CH₂═CH—CH₂)₂CH—OCO—, (CH₂═CH)₂CH—O—,(CH₂═CH—CH₂)₂N—, (CH₂═CH—CH₂)₂N—CO—, HO—CW²W³—, HS—CW²W³—, HW²N—,HO—CW²W³—NH—, CH₂═CW¹—CO—NH—, CH₂═CH—(COO)_(k1)-Phe- (O)_(k2)—,CH₂═CH—(CO)_(k1)-Phe-(O)_(k2)—, Phe-CH═CH—, HOOC—, OCN— and W⁴W⁵W⁶Si—,in which W¹ denotes H, F, Cl, CN, CF₃, phenyl or alkyl having 1 to 5 Catoms, in particular H, F, C₁ or CH₃, W² and W³ each, independently ofone another, denote H or alkyl having 1 to 5 C atoms, in particular H,methyl, ethyl or n-propyl, W⁴, W⁵ and W⁶ each, independently of oneanother, denote Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms,W⁷ and W⁸ each, independently of one another, denote H, Cl or alkylhaving 1 to 5 C atoms, Phe denotes 1,4-phenylene, which is optionallysubstituted by one or more radicals L as defined above which aredifferent from P-Sp-, k₁, k₂ and k₃ each, independently of one another,denote 0 or 1, k₃ preferably denotes 1.

Particularly preferred groups P are CH₂═CW¹—COO—, in particularCH₂═CH—COO—, CH₂═C(CH₃)—COO— and CH₂═CF—COO—, furthermore CH₂═CH—O—,(CH₂═CH)₂CH—OCO—-, (CH₂═CH)₂CH—O—,

Very particularly preferred groups P are vinyloxy, acrylate,methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, inparticular acrylate and methacrylate.

Preferred spacer groups Sp are selected from the formula Sp′-X′, so thatthe radical P-Sp- corresponds to the formula P-Sp′-X′—, where

-   Sp′ denotes alkylene having 1 to 20, preferably 1 to 12, C atoms,    which is optionally mono- or polysubstituted by F, Cl, Br, I or CN    and in which, in addition, one or more non-adjacent CH₂ groups may    each be replaced, independently of one another,    -   by —O—, —S—, —NH—, —NR⁰—, —SiR⁰⁰R⁰⁰⁰—, —CO—, —COO—, —OCO—,        —OCO—O—, —S—CO—, —CO—S—, —NR⁰⁰—CO—O—, —O—CO—NR⁰⁰—,        —NR⁰⁰—CO—NR⁰⁰—, —CH═CH— or —C≡C— in such a way that O and/or S        atoms are not linked directly to one another,-   X′ denotes —O—, —S—, —CO—, —COO—, —OCO—, —O—COO—, —CO—NR⁰⁰—,    —NR⁰⁰—CO—, —NR⁰⁰—CO—NR⁰⁰—, —OCH₂—, —CH₂O—, —SCH₂—, —CH₂S—, —CF₂O—,    —OCF₂—, —CF₂S—, —SCF₂—, —CF₂CH₂—, —CH₂CF₂—, —CF₂CF₂—, —CH═N—,    —N═CH—, —N═N—, —CH═CR⁰—, —CY²═CY³—, —C≡C—, —CH═CH—COO—, —OCO—CH═CH—    or a single bond,-   R⁰⁰ and R⁰⁰⁰ each, independently of one another, denote H or alkyl    having 1 to 12 C atoms, and-   Y² and Y³ each, independently of one another, denote H, F, Cl or CN.-   X′ is preferably —O—, —S—, —CO—, —COO—, —OCO—, —O—COO—, —CO—NR⁰—,    —NR⁰—CO—, —NR⁰—CO—NR⁰— or a single bond.

Typical spacer groups Sp′ are, for

example, —(CH₂)_(p1)—, —(CH₂CH₂O)_(q1)—CH₂CH₂—, —CH₂CH₂—S—CH₂CH₂—,—CH₂CH₂—NH—CH₂CH₂— or —(SiR⁰⁰R⁰⁰⁰—O)_(p1)—, in which p1 is an integerfrom 1 to 12, q1 is an integer from 1 to 3, and R⁰⁰ and R⁰⁰⁰ have themeanings indicated above.

Particularly preferred groups —X′-Sp′— are —(CH₂)_(p1)—, —O—(CH₂)_(p1)—,—OCO—(CH₂)_(p1)—, —OCOO—(CH₂)_(p1)—.

Particularly preferred groups Sp′ are, for example, in each casestraight-chain ethylene, propylene, butylene, pentylene, hexylene,heptylene, octylene, nonylene, decylene, undecylene, dodecylene,octadecylene, ethyleneoxyethylene, methyleneoxybutylene,ethylenethioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene,ethenylene, propenylene and butenylene.

In a further preferred embodiment of the invention, P-Sp- denotes aradical containing two or more polymerisable groups (multifunctionalpolymerisable radicals). Suitable radicals of this type andpolymerisable compounds containing them and the preparation thereof aredescribed, for example, in U.S. Pat. No. 7,060,200 B1 or US 2006/0172090A1. Particular preference is given to multifunctional polymerisableradicals P-Sp- selected from the following formulae:

—X-alkyl-CHP¹—CH₂—CH₂P²  M*a

—X-alkyl-C(CH₂P¹)(CH₂P²)—CH₂P³  M*b

—X-alkyl-CHP¹CHP²—CH₂P³  M*c

—X-alkyl-C(CH₂P¹)(CH₂P²)—C_(aa)H_(2aa+1)  M*d

—X-alkyl-CHP¹—CH₂P²  M*e

—X-alkyl-CHP¹P²  M*f

—X-alkyl-CP¹P²—C_(aa)H_(2aa+1)  M*g

—X-alkyl-C(CH₂P¹)(CH₂P²)—CH₂OCH₂—C(CH₂P³)(CH₂P⁴)CH₂P⁵  M*h

—X-alkyl-CH((CH₂)_(aa)P¹)((CH₂)_(bb)P²)  M*i

—X-alkyl-CHP¹CHP²—C_(aa)H_(2aa+1)  M*k

—X′-alkyl-C(CH₃)(CH₂P¹)(CH₂P²)  M*m

in which

-   alkyl denotes a single bond or straight-chain or branched alkylene    having 1 to 12 C atoms, in which one or more non-adjacent CH₂ groups    may each be replaced, independently of one another, by    —C(R⁰⁰)═C(R⁰⁰⁰)—, —C≡C—, —N(R⁰⁰)—, —O—, —S—, —CO—, —CO—O—, —O—CO—,    —O—CO—O— in such a way that O and/or S atoms are not linked directly    to one another and in which, in addition, one or more H atoms may be    replaced by F, Cl or CN, where R⁰⁰ and R⁰⁰⁰ have the meanings    indicated above,-   aa and bb each, independently of one another, denote 0, 1, 2, 3, 4,    5 or 6,-   X has one of the meanings indicated for X′, and-   P¹⁻⁵ each, independently of one another, have one of the meanings    indicated for P.

The polymerisable compounds and RMs can be prepared analogously toprocesses known to the person skilled in the art and described instandard works of organic chemistry, such as, for example, inHouben-Weyl, Methoden der organischen Chemie [Methods of OrganicChemistry], Thieme-Verlag, Stuttgart. Further synthetic methods aregiven in the documents cited above and below. In the simplest case, thesynthesis of such RMs is carried out, for example, by esterification oretherification of 2,6-dihydroxynaphthalene or 4,4′-dihydroxybiphenylusing corresponding acids, acid derivatives or halogenated compoundscontaining a group P, such as, for example, (meth)acryloyl chloride or(meth)acrylic acid, in the presence of a dehydrating reagent, such as,for example, DCC (dicyclohexylcarbodiimide).

The LC mixtures and LC media according to the invention are in principlesuitable for any type of PS or PSA display, in particular those based onLC media having negative dielectric anisotropy, particularly preferablyfor PSA-VA, PSA-IPS or PS-FFS displays. However, the person skilled inthe art will also be able, without inventive step, to employ suitable LCmixtures and LC media according to the invention in other displays ofthe PS or PSA type which differ from the above-mentioned displays, forexample, through their basic structure or through the nature,arrangement or structure of the individual components used, such as, forexample, the substrates, alignment layers, electrodes, addressingelements, backlighting, polarisers, coloured filters, compensation filmsoptionally present, etc.

Very particularly suitable polymerisable compounds are listed in TableD.

If the liquid-crystalline media according to the invention comprise atleast one polymerisable compound, it is present in the medium in amountsof 0.1 to 10% by weight, preferably 0.2 to 4.0% by weight, particularlypreferably 0.2 to 2.0% by weight.

The mixtures according to the invention may furthermore compriseconventional additives, such as, for example, stabilisers, antioxidants,UV absorbers, nanoparticles, microparticles, etc. Suitable and preferredadditives for the LC mixtures according to the invention are given inTable C.

The structure of the liquid-crystal displays according to the inventioncorresponds to the usual geometry, as described, for example, in EP-A 0240 379.

The following examples are intended to explain the invention withoutlimiting it. Above and below, percent data denote percent by weight; alltemperatures are indicated in degrees Celsius.

Throughout the patent application, 1,4-cyclohexylene rings and1,4-phenylene rings are depicted as follows:

Besides the compounds of the formulae IIA and/or IIB and/or IIC, one ormore compounds of the formula I, the mixtures according to the inventionpreferably comprise one or more of the compounds from Table A indicatedbelow.

TABLE A The following abbreviations are used: (n, m, m′, z: each,independently of one another, 1, 2, 3, 4, 5 or 6; (O)C_(m)H_(2m+1) meansOC_(m)H_(2m+1) or C_(m)H_(2m+1))

The liquid-crystal mixtures which can be used in accordance with theinvention are prepared in a manner which is conventional per se. Ingeneral, the desired amount of the components used in lesser amount isdissolved in the components making up the principal constituent,advantageously at elevated temperature. It is also possible to mixsolutions of the components in an organic solvent, for example inacetone, chloroform or methanol, and to remove the solvent again, forexample by distillation, after thorough mixing.

By means of suitable additives, the liquid-crystal phases according tothe invention can be modified in such a way that they can be employed inany type of, for example, ECB, VAN, IPS, GH or ASM-VA LCD display thathas been disclosed to date.

The dielectrics may also comprise further additives known to the personskilled in the art and described in the literature, such as, forexample, UV absorbers, antioxidants, nanoparticles and free-radicalscavengers. For example, 0-15% of pleochroic dyes, stabilisers or chiraldopants may be added. Suitable stabilisers for the mixtures according tothe invention are, in particular, those listed in Table B.

For example, 0-15% of pleochroic dyes may be added, furthermoreconductive salts, preferably ethyldimethyldodecylammonium4-hexoxybenzoate, tetrabutylammonium tetraphenylboranate or complexsalts of crown ethers (cf., for example, Haller et al., Mol. Cryst. Liq.Cryst., Volume 24, pages 249-258 (1973)), may be added in order toimprove the conductivity or substances may be added in order to modifythe dielectric anisotropy, the viscosity and/or the alignment of thenematic phases. Substances of this type are described, for example, inDE-A 22 09 127, 22 40 864, 23 21 632, 23 38 281, 24 50 088, 26 37 430and 28 53 728.

Table B shows possible dopants which can be added to the mixturesaccording to the invention. If the mixtures comprise a dopant, it isemployed in amounts of 0.01-4% by weight, preferably 0.1-1.0% by weight.

TABLE B

  C 15

  CB 15

  CM 21

  R/S-811

  CM 44

  CM 45

  CM 47

  CN

  R/S-1011

  R/S-2011

  R/S-3011

  R/S-4011

  R/S-5011

Stabilisers which can be added, for example, to the mixtures accordingto the invention in amounts of up to 10% by weight, based on the totalamount of the mixture, preferably 0.01 to 6% by weight, in particular0.1 to 3% by weight, are shown below in Table C. Preferred stabilisersare, in particular, BHT derivatives, for example2,6-di-tert-butyl-4-alkylphenols, and Tinuvin 770.

TABLE C (n = 1-12)

Suitable polymerisable compounds (reactive mesogens) for use in themixtures according to the invention, preferably in PSA, PS-VA, PS-IPSand PS-FFS applications, are shown in Table D below:

Table D shows illustrative compounds which can preferably be used aspolymerisable compounds (reactive mesogenic compounds) in the LC media,preferably for PS-VA, PSA, PS-IPS or PS-FFS applications in accordancewith the present invention.

RM-1

RM-2

RM-3

RM-4

RM-5

RM-6

RM-7

RM-8

RM-9

RM-10

RM-11

RM-12

RM-13

RM-14

RM-15

RM-16

RM-17

RM-18

RM-19

RM-20

RM-21

RM-22

RM-23

RM-24

RM-25

RM-26

RM-27

RM-28

RM-29

RM-30

RM-31

RM-32

RM-33

RM-34

RM-35

RM-36

RM-37

RM-38

RM-39

RM-40

RM-41

RM-42

RM-43

RM-44

RM-45

RM-46

RM-47

RM-48

RM-49

RM-50

RM-51

RM-52

RM-53

RM-54

RM-55

RM-56

RM-57

RM-58

RM-59

RM-60

RM-61

RM-62

RM-63

RM-64

RM-65

RM-66

RM-67

RM-68

RM-69

RM-70

RM-71

RM-72

RM-73

RM-74

RM-75

RM-76

RM-77

RM-78

RM-79

RM-80

RM-81

RM-82

RM-83

In case that the LC medium according to the invention contains one ormore mesogenic compounds, the mesogenic compound is preferably selectedfrom the compounds given in Table D.

WORKING EXAMPLES

The following examples are intended to explain the invention withoutlimiting it. In the examples, m.p. denotes the melting point and Cdenotes the clearing point of a liquid-crystalline substance in degreesCelsius; boiling temperatures are denoted by m.p. Furthermore: C denotescrystalline solid state, S denotes smectic phase (the index denotes thephase type), N denotes nematic state, Ch denotes cholesteric phase, Idenotes isotropic phase, T_(g) denotes glass-transition temperature. Thenumber between two symbols indicates the conversion temperature indegrees Celsius an. The host mixture used for determination of theoptical anisotropy Δn of the compounds of the formula I is thecommercial mixture ZLI-4792 (Merck KGaA). The dielectric anisotropy Δ∈is determined using commercial mixture ZLI-2857. The physical data ofthe compound to be investigated are obtained from the change in thedielectric constants of the host mixture after addition of the compoundto be investigated and extrapolation to 100% of the compound employed.In general, 10% of the compound to be investigated are dissolved in thehost mixture, depending on the solubility.

Unless indicated otherwise, parts or percent data denote parts by weightor percent by weight.

Above and below,

-   V_(o) denotes threshold voltage, capacitive [V] at 20° C.-   Δn denotes the optical anisotropy measured at 20° C. and 589 nm-   Δ∈ denotes the dielectric anisotropy at 20° C. and 1 kHz-   cp., T(N,I) denotes clearing point [° C.]-   K₁ denotes elastic constant, “splay” deformation at 20° C. [pN]-   K₃ denotes elastic constant, “bend” deformation at 20° C. [pN]-   γ₁ denotes rotational viscosity measured at 20° C. [mPa·s],    determined by the rotation method in a magnetic field-   LTS denotes low-temperature stability (nematic phase), determined in    test cells.

The display used for measurement of the threshold voltage has twoplane-parallel outer plates at a separation of 20 μm and electrodelayers with overlying alignment layers of SE-1211 (Nissan Chemicals) onthe insides of the outer plates, which effect a homeotropic alignment ofthe liquid crystals.

All concentrations in this application relate to the correspondingmixture or mixture component, unless explicitly indicated otherwise. Allphysical properties are determined as described in “Merck LiquidCrystals, Physical Properties of Liquid Crystals”, status November 1997,Merck KGaA, Germany, and apply for a temperature of 20° C., unlessexplicitly indicated otherwise.

The display used for measurement of the capacitive threshold voltageconsists of two plane-parallel glass outer plates at a separation of 20μm, each of which has on the inside an electrode layer and an unrubbedpolyimide alignment layer on top, which effect a homeotropic edgealignment of the liquid-crystal molecules.

The display or test cell used for measurement of the tilt anglesconsists of two plane-parallel glass outer plates at a separation of 4μm, each of which has on the inside an electrode layer and a polyimidealignment layer on top, where the two polyimide layers are rubbedantiparallel to one another and effect a homeotropic edge alignment ofthe liquid-crystal molecules.

The polymerisable compounds are polymerised in the display or test cellby irradiation with UVA light (for example at 365 nm) of definedintensity for a prespecified time, with a voltage simultaneously beingapplied to the display (usually 10 V to 30 V alternating current, 1kHz). In the examples, unless indicated otherwise, a metal halide lampand an intensity of 100 mW/cm² is used for polymerisation. The intensityis measured using a standard UVA meter (Hoenle UV-meter high end withUVA sensor).

MIXTURE EXAMPLES Example M1

PY-3-O2 8.00% Clearing point [° C.]: 74.5 PY-3-O4 9.00% Δn [589 nm, 20°C.]: 0.1172 CCY-3-O3 8.00% Δε [1 kHz, 20° C.]: −3.1 CCY-4-O2 6.50%ε_(||) [1 kHz, 20° C.]: 3.5 CPY-2-O2 10.00% K₃ [pN, 20° C.]: 12.9CPY-3-O2 10.00% K₃/K₁ [20° C.]: 0.94 CCH-34 10.00% γ₁ [mPa · s, 20° C.]:116 CCH-23 22.00% V₀ [20° C., V]: 2.14 PYP-2-3 8.00% PYP-2-4 4.00%PCH-301 4.50%

Example M2

PY-3-O2 7.00% Clearing point [° C.]: 74.5 PY-3-O4 7.00% Δn [589 nm, 20°C.]: 0.1169 CY-3-O2 2.50% Δε [1 kHz, 20° C.]: −3.1 CCY-3-O3 8.00% ε_(||)[1 kHz, 20° C.]: 3.5 CCY-4-O2 6.00% K₃ [pN, 20° C.]: 12.8 CPY-2-O210.00% K₃/K₁ [20° C.]: 0.96 CPY-3-O2 10.00% γ₁ [mPa · s, 20° C.]: 116CCH-34 10.00% V₀ [20° C., V]: 2.14 CCH-23 21.00% PYP-2-3 8.00% PYP-2-45.00% PCH-301 5.50%

Example M3

PY-3-O2 10.00% Clearing point [° C.]: 69.0 PY-3-O4 10.00% Δn [589 nm,20° C.]: 0.1199 CCY-3-O3 4.00% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O2 10.00%ε_(||) [1 kHz, 20° C.]: 3.5 CPY-2-O2 7.00% K₃ [pN, 20° C.]: 13.5CPY-3-O2 10.00% K₃/K₁ [20° C.]: 0.94 CCH-34 11.00% γ₁ [mPa · s, 20° C.]:104 CCH-23 20.00% V₀ [20° C., V]: 2.23 PYP-2-3 7.00% PYP-2-4 1.50%CCP-3-1 2.50% PP-1-3 7.00%

Example M4

BCH-32 6.50% Clearing point [° C.]: 74.5 CCP-3-1 6.00% Δn [589 nm, 20°C.]: 0.1021 CCH-23 20.00% Δε [1 kHz, 20° C.]: −3.1 CCH-34 3.00% ε_(||)[1 kHz, 20° C.]: 3.6 CCH-35 3.00% K₃ [pN, 20° C.]: 14.5 CCY-3-O2 10.00%K₃/K₁ [20° C.]: 0.99 CCY-3-O1 5.50% γ₁ [mPa · s, 20° C.]: 97 CPY-2-O26.00% V₀ [20° C., V]: 2.30 CPY-3-O2 10.00% Y-4O-O4 8.00% PY-3-O2 9.00%PY-3-O4 2.50% PYP-2-3 1.50% CC-3-V1 9.00%

Example M5

CY-3-O2 10.00% Clearing point [° C.]: 77.5 PY-3-O2 6.00% Δn [589 nm, 20°C.]: 0.0957 PY-1-O2 6.00% Δε [1 kHz, 20° C.]: −3.0 CLY-2-O4 5.00% ε_(||)[1 kHz, 20° C.]: 3.4 CLY-3-O2 4.00% K₃ [pN, 20° C.]: 15.0 CLY-3-O3 4.00%K₃/K₁ [20° C.]: 1.01 CCY-4-O2 8.00% γ₁ [mPa · s, 20° C.]: 106 CPY-3-O28.00% V₀ [20° C., V]: 2.37 CCH-34 6.00% CCH-23 22.00% CCP-3-3 6.00%CCP-3-1 8.50% PCH-301 6.50%

Example M6

CY-3-O2 3.00% Clearing point [° C.]: 74.0 PY-3-O2 7.00% Δn [589 nm, 20°C.]: 0.1040 PY-1-O2 7.00% Δε [1 kHz, 20° C.]: −2.9 CPY-2-O2 7.00% ε_(||)[1 kHz, 20° C.]: 3.5 CPY-3-O2 8.00% K₃ [pN, 20° C.]: 13.5 CCH-34 10.00%K₃/K₁ [20° C.]: 0.99 CCH-23 20.00% γ₁ [mPa · s, 20° C.]: 105 CCP-3-34.00% V₀ [20° C., V]: 2.26 BCH-32 3.50% PCH-301 11.50% CLY-2-O4 7.00%CLY-3-O2 5.00% CLY-3-O3 7.00%

Example M7

CY-3-O2 7.00% Clearing point [° C.]: 75.0 PY-3-O2 8.00% Δn [589 nm, 20°C.]: 0.1075 PY-3-O4 8.00% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O2 4.00% ε_(||)[1 kHz, 20° C.]: 3.5 CLY-3-O2 8.00% K₃ [pN, 20° C.]: 15.1 CPY-2-O2 8.00%K₃/K₁ [20° C.]: 1.09 CPY-3-O2 9.00% γ₁ [mPa · s, 20° C.]: 87 PYP-2-33.00% V₀ [20° C., V]: 2.37 CC-3-V 36.50% CCP-3-1 8.50%

Example M8

CLY-3-O2 11.50% Clearing point [° C.]: 74.0 CPY-2-O2 8.00% Δn [589 nm,20° C.]: 0.1150 CPY-3-O2 14.00% Δε [1 kHz, 20° C.]: −2.9 CC-3-V 43.00%ε_(||) [1 kHz, 20° C.]: 3.5 PY-3-O2 10.00% K₃ [pN, 20° C.]: 14.7 PY-3-O47.00% K₃/K₁ [20° C.]: 1.06 PYP-2-3 5.00% γ₁ [mPa · s, 20° C.]: 82PGP-2-4 1.50% V₀ [20° C., V]: 2.39

Example M9

PY-4-O2 8.00% Clearing point [° C.]: 74.0 PY-1-O4 8.00% Δn [589 nm, 20°C.]: 0.0958 CCY-3-O1 7.00% Δε [1 kHz, 20° C.]: −2.2 CCY-3-O2 8.00%ε_(||) [1 kHz, 20° C.]: 3.2 CPY-3-O2 10.00% K₃ [pN, 20° C.]: 14.5 CCH-2320.00% K₃/K₁ [20° C.]: 1.01 CCH-34 5.00% γ₁ [mPa · s, 20° C.]: 90 CCH-355.00% V₀ [20° C., V]: 2.73 PCH-302 10.50% CCH-301 6.00% CCP-3-1 7.50%BCH-32 5.00%

Example M10

BCH-32 3.00% Clearing point [° C.]: 75.0 CCH-23 21.00% Δn [589 nm, 20°C.]: 0.0952 CCH-34 6.00% Δε [1 kHz, 20° C.]: −2.3 CCP-3-1 12.00% ε_(||)[1 kHz, 20° C.]: 3.4 CCP-3-3 6.00% K₃ [pN, 20° C.]: 14.8 CCY-3-O1 5.50%K₃/K₁ [20° C.]: 1.02 CCY-3-O2 9.00% γ₁ [mPa · s, 20° C.]: 93 CPY-3-O29.50% V₀ [20° C., V]: 2.67 PYP-2-3 3.00% PCH-302 10.00% PY-4-O2 3.50%PY-1-O4 3.50% Y-4O-O4 8.00%

Example M11

PY-4-O2 7.00% Clearing point [° C.]: 75.5 PY-1-O4 8.00% Δn [589 nm, 20°C.]: 0.1074 CCY-3-O1 7.00% Δε [1 kHz, 20° C.]: −2.2 CCY-3-O2 9.00%ε_(||) [1 kHz, 20° C.]: 3.2 CPY-3-O2 8.50% K₃ [pN, 20° C.]: 14.6 PYP-2-33.50% K₃/K₁ [20° C.]: 1.00% CCH-23 20.00% γ₁ [mPa · s, 20° C.]: 98CCH-34 5.00% V₀ [20° C., V]: 2.74 CCH-35 5.00% PCH-302 15.00% BCH-3212.00%

Example M12

Y-4O-O4 7.00% Clearing point [° C.]: 74.5 PY-4-O2 3.50% Δn [589 nm, 20°C.]: 0.1069 PY-1-O4 3.50% Δε [1 kHz, 20° C.]: −2.0 CCY-3-O2 8.50% ε_(||)[1 kHz, 20° C.]: 3.3 CPY-3-O2 10.00% K₃ [pN, 20° C.]: 14.2 PYP-2-3 9.50%K₃/K₁ [20° C.]: 0.97 CCH-23 19.00% γ₁ [mPa · s, 20° C.]: 88 CCH-34 6.00%V₀ [20° C., V]: 2.80 CCH-35 6.00% PCH-302 8.50% BCH-32 8.50% CCP-3-110.00%

Example M13

PY-3-O2 12.00% Clearing point [° C.]: 74.0 PY-2-O2 11.00% Δn [589 nm,20° C.]: 0.1079 CCY-3-O1 6.00% Δε [1 kHz, 20° C.]: −3.1 CCY-3-O2 8.50%ε_(||) [1 kHz, 20° C.]: 3.7 CPY-2-O2 7.00% K₃ [pN, 20° C.]: 15.0CPY-3-O2 10.00% K₃/K₁ [20° C.]: 1.11 CC-3-V 36.50% γ₁ [mPa · s, 20° C.]:85 CCP-3-1 8.50% V₀ [20° C., V]: 2.34 PPGU-3-F 0.50%

Example M14

CY-3-O2 3.50% Clearing point [° C.]: 75.0 PY-3-O2 9.00% Δn [589 nm, 20°C.]: 0.1025 PY-2-O2 6.00% Δε [1 kHz, 20° C.]: −3.1 CCY-3-O2 9.00% ε_(||)[1 kHz, 20° C.]: 3.5 CCY-3-O1 6.00% K₃ [pN, 20° C.]: 14.2 CCY-4-O2 2.00%K₃/K₁ [20° C.]: 1.04 CPY-2-O2 8.00% γ₁ [mPa · s, 20° C.]: 103 CPY-3-O210.00% V₀ [20° C., V]: 2.27 CCH-34 10.00% CCH-23 21.00% BCH-32 3.00%CCP-3-1 4.00% PCH-301 8.50%

Example M15

PY-3-O2 10.00% Clearing point [° C.]: 75.0 PY-2-O2 9.00% Δn [589 nm, 20°C.]: 0.1035 CCY-3-O2 9.00% Δε [1 kHz, 20° C.]: −3.1 CCY-3-O1 6.00%ε_(||) [1 kHz, 20° C.]: 3.5 CCY-4-O2 3.00% K₃ [pN, 20° C.]: 14.4CPY-2-O2 7.00% K₃/K₁ [20° C.]: 1.04 CPY-3-O2 10.00% γ₁ [mPa · s, 20°C.]: 103 CCH-34 10.00% V₀ [20° C., V]: 2.26 CCH-23 20.00% CCP-3-1 7.00%PCH-301 9.00%

Example M16

CY-3-O2 8.00% Clearing point [° C.]: 79.5 PY-2-O2 8.00% Δn [589 nm, 20°C.]: 0.0948 PY-1-O2 6.50% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O2 5.00% ε_(||)[1 kHz, 20° C.]: 3.4 CCY-3-O3 8.00% K₃ [pN, 20° C.]: 15.1 CCY-4-O2 8.00%K₃/K₁ [20° C.]: 1.05 CPY-3-O2 8.00% γ₁ [mPa · s, 20° C.]: 110 CCH-346.00% V₀ [20° C., V]: 2.38 CCH-23 22.00% CCP-3-3 7.50% CCP-3-1 8.50%PCH-301 4.50%

Example M17

PY-4-O2 8.00% Clearing point [° C.]: 74.0 PY-1-O4 8.00% Δn [589 nm, 20°C.]: 0.0958 CCY-3-O1 7.00% Δε [1 kHz, 20° C.]: −2.2 CCY-3-O2 8.00%ε_(||) [1 kHz, 20° C.]: 3.2 CPY-3-O2 10.00% K₃ [pN, 20° C.]: 14.5 CCH-2320.00% K₃/K₁ [20° C.]: 1.01 CCH-34 5.00% γ₁ [mPa · s, 20° C.]: 90 CCH-355.00% V₀ [20° C., V]: 2.73 PCH-302 10.50% CCH-301 6.00% CCP-3-1 7.50%BCH-32 5.00%

Example M18

PY-3-O2 11.00% Clearing point [° C.]: 74.0 PY-1-O4 6.50% Δn [589 nm, 20°C.]: 0.1093 CY-3-O2 5.00% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O1 6.00% ε_(||)[1 kHz, 20° C.]: 3.7 CCY-3-O2 8.00% K₃ [pN, 20° C.]: 14.6 CPY-2-O2 8.50%K₃/K₁ [20° C.]: 1.11 CPY-3-O2 10.00% γ₁ [mPa · s, 20° C.]: 87 CC-3-V37.50% V₀ [20° C., V]: 2.32 BCH-32 7.00% PPGU-3-F 0.50%

Example M19

CY-3-O2 4.00% Clearing point [° C.]: 75.0 PY-3-O2 9.00% Δn [589 nm, 20°C.]: 0.1022 PY-4-O2 6.00% Δε [1 kHz, 20° C.]: −3.1 CCY-3-O2 9.00% ε_(||)[1 kHz, 20° C.]: 3.5 CCY-3-O1 6.00% K₃ [pN, 20° C.]: 14.1 CCY-4-O2 2.00%K₃/K₁ [20° C.]: 1.03 CPY-2-O2 8.00% γ₁ [mPa · s, 20° C.]: 104 CPY-3-O210.00% V₀ [20° C., V]: 2.26 CCH-34 10.00% CCH-23 21.00% BCH-32 3.50%CCP-3-1 3.00% PCH-301 8.50%

Example M20

PY-3-O2 12.00% Clearing point [° C.]: 74.0 PY-4-O2 11.00% Δn [589 nm,20° C.]: 0.1075 CCY-3-O1 6.00% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O2 8.00%ε_(||) [1 kHz, 20° C.]: 3.7 CPY-2-O2 8.00% K₃ [pN, 20° C.]: 14.7CPY-3-O2 10.00% K₃/K₁ [20° C.]: 1.09 CC-3-V 37.00% γ₁ [mPa · s, 20° C.]:87 CCP-3-1 7.50% V₀ [20° C., V]: 2.35 PPGU-3-F 0.50%

Example M21

PY-3-O2 6.50% Clearing point [° C.]: 75.0 PY-1-O4 6.00% Δn [589 nm, 20°C.]: 0.1039 PY-4-O2 6.00% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O2 9.00% ε_(||)[1 kHz, 20° C.]: 3.5 CCY-3-O1 5.00% K₃ [pN, 20° C.]: 14.1 CCY-4-O2 3.50%K₃/K₁ [20° C.]: 1.01 CPY-2-O2 7.00% γ₁ [mPa · s, 20° C.]: 105 CPY-3-O210.00% V₀ [20° C., V]: 2.29 CCH-34 10.00% CCH-23 20.00% BCH-32 3.50%CCP-3-1 3.50% PCH-301 10.00%

Example M22

PY-3-O2 12.00% Clearing point [° C.]: 74.0 PY-1-O4 6.00% Δn [589 nm, 20°C.]: 0.1080 PY-4-O2 5.00% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O1 5.50% ε_(||)[1 kHz, 20° C.]: 3.7 CCY-3-O2 9.00% K₃ [pN, 20° C.]: 14.9 CPY-2-O2 7.00%K₃/K₁ [20° C.]: 1.10 CPY-3-O2 10.00% γ₁ [mPa · s, 20° C.]: 86 CC-3-V37.50% V₀ [20° C., V]: 2.36 CCP-3-1 6.00% BCH-32 1.50% PPGU-3-F 0.50%

Example M23

CY-3-O2 2.00% Clearing point [° C.]: 74.5 PY-3-O2 7.00% Δn [589 nm, 20°C.]: 0.1030 PY-1-O4 5.50% Δε [1 kHz, 20° C.]: −3.0 PY-4-O2 4.00% ε_(||)[1 kHz, 20° C.]: 3.5 CCY-3-O2 9.00% K₃ [pN, 20° C.]: 14.2 CCY-3-O1 6.00%K₃/K₁ [20° C.]: 1.04 CCY-4-O2 2.00% γ₁ [mPa · s, 20° C.]: 105 CPY-2-O28.00% V₀ [20° C., V]: 2.28 CPY-3-O2 10.00% CCH-34 10.00% CCH-23 20.00%BCH-32 3.00% CCP-3-1 3.50% PCH-301 10.00%

Example M24

CY-3-O2 4.00% Clearing point [° C.]: 73.5 PY-3-O2 7.00% Δn [589 nm, 20°C.]: 0.1034 PY-1-O4 5.50% Δε [1 kHz, 20° C.]: −3.1 PY-4-O2 4.00% ε_(||)[1 kHz, 20° C.]: 3.5 CCY-3-O2 10.00% K₃ [pN, 20° C.]: 14.5 CCY-3-O16.00% K₃/K₁ [20° C.]: 1.01 CCY-4-O2 6.00% γ₁ [mPa · s, 20° C.]: 105CPY-2-O2 3.00% V₀ [20° C., V]: 2.28 CPY-3-O2 10.00% CCH-34 10.00% CCH-2320.00% CCP-3-1 6.00% PCH-301 2.50% PP-1-3 6.00%

Example M25

PY-3-O2 6.00% Clearing point [° C.]: 73.0 PY-4-O2 8.00% Δn [589 nm, 20°C.]: 0.1175 PY-1-O4 6.50% Δε [1 kHz, 20° C.]: −3.5 CCY-3-O3 5.00% ε_(||)[1 kHz, 20° C.]: 3.6 CCY-3-O2 12.00% K₃ [pN, 20° C.]: 13.9 CPY-2-O28.00% K₃/K₁ [20° C.]: 0.96 CPY-3-O2 12.00% γ₁ [mPa · s, 20° C.]: 116CCH-34 10.00% V₀ [20° C., V]: 2.12 CCH-23 21.00% PYP-2-3 4.00% PYP-2-42.00% CCP-3-1 1.00% PP-1-3 4.50%

Example M26

PY-3-O2 10.00% Clearing point [° C.]: 75.0 PY-1-O4 5.00% Δn [589 nm, 20°C.]: 0.1101 PY-3-O4 2.00% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O2 10.00%ε_(||) [1 kHz, 20° C.]: 3.5 CCY-4-O2 4.50% K₃ [pN, 20° C.]: 13.9CCY-3-O1 6.00% K₃/K₁ [20° C.]: 1.08 CPY-2-O2 3.00% γ₁ [mPa · s, 20° C.]:108 CPY-3-O2 10.00% V₀ [20° C., V]: 2.27 CCH-34 10.00% CCH-23 21.00%PYP-2-3 7.00% BCH-32 2.50% PCH-301 9.00%

Example M27

CY-3-O2 2.50% Clearing point [° C.]: 75.0 PY-3-O2 6.00% Δn [589 nm, 20°C.]: 0.1025 PY-1-O4 5.00% Δε [1 kHz, 20° C.]: −3.1 PY-2-O2 5.00% ε_(||)[1 kHz, 20° C.]: 3.5 CCY-3-O2 9.00% K₃ [pN, 20° C.]: 14.3 CCY-3-O1 5.00%K₃/K₁ [20° C.]: 1.05 CCY-4-O2 3.00% γ₁ [mPa · s, 20° C.]: 104 CPY-2-O28.00% V₀ [20° C., V]: 2.27 CPY-3-O2 10.00% CCH-34 10.00% CCH-23 20.00%BCH-32 3.00% CCP-3-1 4.00% PCH-301 9.50%

Example M28

PY-3-O2 10.00% Clearing point [° C.]: 73.5 PY-1-O4 7.00% Δn [589 nm, 20°C.]: 0.1104 PY-3-O4 6.00% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O2 9.00% ε_(||)[1 kHz, 20° C.]: 3.5 CCY-3-O1 6.00% K₃ [pN, 20° C.]: 14.0 CPY-2-O2 5.50%K₃/K₁ [20° C.]: 0.99 CPY-3-O2 10.00% γ₁ [mPa · s, 20° C.]: 105 CCH-3410.00% γV₀ [20° C., V]: 2.27 CCH-23 20.00% CCP-3-1 2.00% BCH-32 8.50%PCH-301 6.00%

Example M29

PY-3-O2 7.00% Clearing point [° C.]: 73.5 PY-1-O4 6.00% Δn [589 nm, 20°C.]: 0.1105 PY-2-O2 5.00% Δε [1 kHz, 20° C.]: −3.0 PY-3-O4 5.00% ε_(||)[1 kHz, 20° C.]: 3.5 CCY-3-O2 9.00% K₃ [pN, 20° C.]: 13.9 CCY-3-O1 6.00%K₃/K₁ [20° C.]: 1.00% CPY-2-O2 5.50% γ₁ [mPa · s, 20° C.]: 103 CPY-3-O210.00% V₀ [20° C., V]: 2.25 CCH-34 10.00% CCH-23 20.00% CCP-3-1 2.50%BCH-32 8.50% PCH-301 5.50%

Example M30

PY-3-O2 12.00% Clearing point [° C.]: 74.0 PY-1-O4 6.00% Δn [589 nm, 20°C.]: 0.1077 PY-2-O2 5.00% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O1 5.50% ε_(||)[1 kHz, 20° C.]: 3.7 CCY-3-O2 9.00% K₃ [pN, 20° C.]: 15.1 CPY-2-O2 7.00%K₃/K₁ [20° C.]: 1.11 CPY-3-O2 10.00% γ₁ [mPa · s, 20° C.]: 86 CC-3-V37.00% V₀ [20° C., V]: 2.36 CCP-3-1 8.00% PPGU-3-F 0.50%

Example M31

PY-3-O2 12.00% Clearing point [° C.]: 74.0 PY-1-O4 6.00% Δn [589 nm, 20°C.]: 0.1080 PY-4-O2 5.00% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O1 5.50% ε_(||)[1 kHz, 20° C.]: 3.7 CCY-3-O2 9.00% K₃ [pN, 20° C.]: 14.9 CPY-2-O2 7.00%K₃/K₁ [20° C.]: 1.10 CPY-3-O2 10.00% γ₁ [mPa · s, 20° C.]: 86 CC-3-V37.50% V₀ [20° C., V]: 2.36 CCP-3-1 6.00% BCH-32 1.50% PPGU-3-F 0.50%

Example M32

PY-3-O2 10.00% Clearing point [° C.]: 75.0 PY-2-O2 5.00% Δn [589 nm, 20°C.]: 0.1098 PY-3-O4 2.50% Δε [1 kHz, 20° C.]: −3.1 CCY-3-O2 9.00% ε_(||)[1 kHz, 20° C.]: 3.5 CCY-4-O2 5.00% K₃ [pN, 20° C.]: 14.0 CCY-3-O1 5.50%K₃/K₁ [20° C.]: 1.02 CPY-2-O2 4.00% γ₁ [mPa · s, 20° C.]: 107 CPY-3-O210.00% V₀ [20° C., V]: 2.25 CCH-34 10.00% CCH-23 20.00% PYP-2-3 6.50%CCP-3-1 2.00% BCH-32 1.50% PCH-301 9.00%

Example M33

PY-3-O2 10.00% Clearing point [° C.]: 75.0 PY-2-O2 5.00% Δn [589 nm, 20°C.]: 0.1098 PY-3-O4 2.50% Δε [1 kHz, 20° C.]: −3.1 CCY-3-O2 9.00% ε_(||)[1 kHz, 20° C.]: 3.5 CCY-4-O2 5.00% K₃ [pN, 20° C.]: 14.0 CCY-3-O1 5.50%K₃/K₁ [20° C.]: 1.02 CPY-2-O2 4.00% γ₁ [mPa · s, 20° C.]: 107 CPY-3-O210.00% V₀ [20° C., V]: 2.25 CCH-34 10.00% CCH-23 20.00% PYP-2-3 6.50%CCP-3-1 2.00% BCH-32 1.50% PCH-301 9.00%

Example M34

PY-3-O2 10.00% Clearing point [° C.]: 75.0 PY-1-O4 5.00% Δn [589 nm, 20°C.]: 0.1101 PY-3-O4 2.00% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O2 10.00%ε_(||) [1 kHz, 20° C.]: 3.5 CCY-4-O2 4.50% K₃ [pN, 20° C.]: 13.9CCY-3-O1 6.00% K₃/K₁ [20° C.]: 1.08 CPY-2-O2 3.00% γ₁ [mPa · s, 20° C.]:108 CPY-3-O2 10.00% V₀ [20° C., V]: 2.27 CCH-34 10.00% CCH-23 21.00%PYP-2-3 7.00% BCH-32 2.50% PCH-301 9.00%

Example M35

CY-3-O2 2.50% Clearing point [° C.]: 75.0 PY-3-O2 6.00% Δn [589 nm, 20°C.]: 0.1025 PY-1-O4 5.00% Δε [1 kHz, 20° C.]: −3.1 PY-2-O2 5.00% ε_(||)[1 kHz, 20° C.]: 3.5 CCY-3-O2 9.00% K₃ [pN, 20° C.]: 14.3 CCY-3-O1 5.00%K₃/K₁ [20° C.]: 1.05 CCY-4-O2 3.00% γ₁ [mPa · s, 20° C.]: 104 CPY-2-O28.00% V₀ [20° C., V]: 2.27 CPY-3-O2 10.00% CCH-34 10.00% CCH-23 20.00%BCH-32 3.00% CCP-3-1 4.00% PCH-301 9.50%

Example M36

PY-4-O2 5.00% Clearing point [° C.]: 75.0 PY-1-O4 4.00% Δn [589 nm, 20°C.]: 0.1072 PY-3-O2 8.00% Δε [1 kHz, 20° C.]: −1.9 CPY-2-O2 10.00%ε_(||) [1 kHz, 20° C.]: 3.2 CPY-3-O2 10.00% K₃ [pN, 20° C.]: 13.6 BCH-3212.00% K₃/K₁ [20° C.]: 0.93 CCP-3-1 7.00% γ₁ [mPa · s, 20° C.]: 86CCH-23 15.00% V₀ [20° C., V]: 2.84 CCH-34 7.00% CCH-35 10.00% CCH-3016.00% PCH-301 6.00%

Example M37

CCY-3-O2 7.50% Clearing point [° C.]: 75.0 CCY-3-O1 8.00% Δn [589 nm,20° C.]: 0.0902 CCY-3-O3 5.00% Δε [1 kHz, 20° C.]: −3.9 CCY-4-O2 8.50%ε_(||) [1 kHz, 20° C.]: 3.7 CPY-2-O2 5.00% K₃ [pN, 20° C.]: 15.0CPY-3-O2 6.00% K₃/K₁ [20° C.]: 1.18 CY-3-O2 18.00% γ₁ [mPa · s, 20° C.]:99 PY-3-O2 6.00% V₀ [20° C., V]: 2.08 CC-3-V 35.50%

Example M38

For the preparation of a PS-FFS mixture or PS-IPS mixture, 0.25% of thepolymerisable compound of the formula

are added to 99.75% of the mixture according to Example M37.

Example M39

For the preparation of a PS-FFS mixture or PS-IPS mixture, 0.25% of thepolymerisable compound of the formula

are added to 99.75% of the mixture according to Example M37.

Example M40

For the preparation of a PS-FFS mixture or PS-IPS mixture, 0.4% of thepolymerisable compound of the formula

are added to 99.6% of the mixture according to Example M37, causing thevoltage holding ratio of mixture M37 to be significantly increased(VHR>90% after UV exposure).

Example M41

PY-3-O2 10.00% Clearing point [° C.]: 73.5 PY-1-O4 7.00% Δn [589 nm, 20°C.]: 0.1105 PY-3-O4 6.00% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O2 9.00% ε_(||)[1 kHz, 20° C.]: 3.5 CCY-3-O1 5.00% K₃ [pN, 20° C.]: 13.8 CPY-2-O2 6.50%K₃/K₁ [20° C.]: 0.97 CPY-3-O2 10.00% γ₁ [mPa · s, 20° C.]: 105 CCH-3410.00% V₀ [20° C., V]: 2.26 CCH-23 21.00% CCP-3-1 2.00% BCH-32 8.50%PCH-301 5.00%

Example M42

PY-4-O2 10.00% Clearing point [° C.]: 70.5 PY-1-O4 8.00% Δn [589 nm, 20°C.]: 0.1158 CCY-3-O2 10.00% Δε [1 kHz, 20° C.]: −3.0 CPY-3-O2 12.00% γ₁[mPa · s, 20° C.]: 105 CLY-3-O2 8.00% PYP-2-3 5.00% PYP-2-4 5.00% CCH-356.00% CCH-23 21.00% PCH-301 8.00% PP-1-2V1 7.00%

Example M43

PY-3-O2 6.50% Clearing point [° C.]: 73.0 PY-1-O4 6.00% Δn [589 nm, 20°C.]: 0.1018 PY-4-O2 6.00% Δε [1 kHz, 20° C.]: −2.9 CCP-304FCI 6.00% γ₁[mPa · s, 20° C.]: 111 CCP-302FCI 5.00% CCY-4-O2 6.50% CPY-2-O2 7.00%CPY-3-O2 10.00% CCH-34 10.00% CCH-23 20.00% BCH-32 3.50% CCP-3-1 3.50%PCH-301 10.00%

Example M44

For the preparation of a PS-VA mixture, 0.2% of the polymerisablecompound of the formula

are added to 99.8% of the mixture according to Example M6.

The PS-VA mixture is introduced into a cell having homeotropicalignment. After application of a voltage of 24 V, the cell isirradiated with UV light with a power of 100 mW/cm².

Example M45

For the preparation of a PS-VA mixture, 0.2% of the polymerisablecompound of the formula

are added to 99.8% of the mixture according to Example M6.

The PS-VA mixture is introduced into a cell having homeotropicalignment. After application of a voltage of 24 V, the cell isirradiated with UV light with a power of 100 mW/cm².

Example M46

For the preparation of a PS-VA mixture, 0.2% of the polymerisablecompound of the formula

are added to 99.8% of the mixture according to Example M6.

The PS-VA mixture is introduced into a cell having homeotropicalignment. After application of a voltage of 24 V, the cell isirradiated with UV light with a power of 100 mW/cm².

Example M47

CC-3-V 28.50% Clearing point [° C.]: 75.1 CC-3-V1 5.00% Δn [589 nm, 20°C.]: 0.1090 CCH-34 6.50% Δε [1 kHz, 20° C.]: −3.0 CCY-3-O3 9.50% ε_(||)[1 kHz, 20° C.]: 3.6 CCY-4-O2 10.00% K₁ [pN, 20° C.]: 13.5 CPY-2-O27.50% K₃/K₁ [20° C.]: 1.02 CPY-3-O2 6.50% V₀ [20° C., V]: 2.26 PY-1-O45.00% PY-3-O2 14.50% PYP-2-4 6.50% PPGU-3-F 0.50%

Example M48

For the preparation of a PS-VA mixture, 0.45% of the polymerisablecompound of the formula

are added to 99.55% of the mixture according to Example M45.

The PS-VA mixture is introduced into a cell having homeotropicalignment. After application of a voltage of 24 V, the cell isirradiated with UV light with a power of 100 mW/cm².

Example M49

CCY-3-O1 5.00% Clearing point [° C.]: 79.8 CCY-3-O2 8.00% Δn [589 nm,20° C.]: 0.1406 CCY-3-O3 8.00% Δε [1 kHz, 20° C.]: −7.0 CCY-4-O2 8.00%K₁ [pN, 25° C.]: 13.0 CCY-5-O2 2.00% K₃ [pN, 25° C.]: 15.3 CPY-2-O210.00% V₀ [25° C., V]: 1.56 CPY-3-O2 10.00% CY-3-O2 8.00% CY-3-O4 5.00%PY-1-O4 12.00% PY-3-O2 6.00% PY-4-O2 12.00% PYP-2-3 6.00%

Example M50

CC-4-V 4.00% Clearing point [° C.]: 80.2 CCY-3-O1 5.50% Δn [589 nm, 20°C.]: 0.1401 CCY-3-O2 8.00% Δε [1 kHz, 20° C.]: −6.5 CCY-3-O3 8.00% K₁[pN, 25° C.]: 13.4 CCY-4-O2 8.00% K₃ [pN, 25° C.]: 14.5 CPY-2-O2 10.00%V₀ [25° C., V]: 1.59 CPY-3-O2 10.00% CY-3-O2 4.00% CY-3-O4 5.00% PY-1-O412.00% PY-3-O2 6.00% PY-4-O2 12.00% PYP-2-3 7.50%

Example M51

CC-4-V 3.50% Clearing point [° C.]: 74.8 CCY-3-O1 5.00% Δn [589 nm, 20°C.]: 0.1392 CCY-3-O2 8.00% Δε [1 kHz, 20° C.]: −6.5 CCY-4-O2 8.00% K₁[pN, 25° C.]: 12.6 CCY-5-O2 5.00% K₃ [pN, 25° C.]: 14.6 CPY-2-O2 10.00%V₀ [25° C., V]: 1.58 CPY-3-O2 10.00% CY-3-O2 8.00% CY-3-O4 5.00% PY-1-O412.00% PY-3-O2 6.00% PY-4-O2 12.00% PYP-2-3 7.50%

Example M52

CCH-23 20.00% Clearing point [° C.]: 76.0 CCH-34 6.00% Δn [589 nm, 20°C.]: 0.0987 CCH-35 3.00% Δε [1 kHz, 20° C.]: −3.1 CCH-301 6.00% γ₁ [mPa· s, 20° C.]: 107 PCH-301 6.00% K₁ [pN, 20° C.]: 13.9 CCP-3-1 6.50% K₃[pN, 20° C.]: 14.3 CCY-3-O1 5.00% V₀ [20° C., V]: 2.26 CCY-3-O2 5.00%CCY-4-O2 3.50% COY-3-O2 5.00% PY-3-O2 8.00% PY-4-O2 4.00% CPY-2-O210.00% CPY-3-O2 12.00%

Example M53

CCH-23 20.00% Clearing point [° C.]: 76.0 CCH-34 6.00% Δn [589 nm, 20°C.]: 0.0988 CCH-35 3.00% Δε [1 kHz, 20° C.]: −3.2 CCH-301 6.00% γ₁ [mPa· s, 20° C.]: 108 PCH-301 6.00% K₁ [pN, 20° C.]: 13.9 CCP-3-1 5.50% K₃[pN, 20° C.]: 14.2 CCY-3-O1 4.50% V₀ [20° C., V]: 2.24 CCY-3-O2 5.00%CCY-4-O2 3.00% CCOY-2-O2 4.00% COY-3-O2 3.00% PY-3-O2 8.00% PY-4-O24.00% CPY-2-O2 10.00% CPY-3-O2 11.00% PP-1-3 1.00%

Example M54

CC-3-V 28.00% Clearing point [° C.]: 74.0 CY-3-O2 10.00% Δn [589 nm, 20°C.]: 0.1082 CCY-3-O1 5.50% Δε [1 kHz, 20° C.]: −3.5 CCY-3-O2 11.00% γ₁[mPa · s, 20° C.]: 101 CCY-4-O2 5.00% K₁ [pN, 20° C.]: 13.9 CPY-3-O211.00% K₃ [pN, 20° C.]: 16.1 PY-3-O2 11.50% V₀ [20° C., V]: 2.27 PY-1-O43.00% PYP-2-3 5.00% PP-1-2V1 2.00% CC-3-2V1 8.00%

Example M55

CC-3-V 32.50% Clearing point [° C.]: 75.1 CC-3-V1 9.50% Δn [589 nm, 20°C.]: 0.1092 CCY-3-O1 9.50% Δε [1 kHz, 20° C.]: −3.2 CCY-3-O2 4.50% γ₁[mPa · s, 20° C.]: 91 CLY-3-O2 10.00% K₁ [pN, 20° C.]: 13.9 CPY-3-O28.00% K₃ [pN, 20° C.]: 16.4 PY-1-O4 4.00% V₀ [20° C., V]: 2.39 PY-3-O217.00% PYP-2-3 5.00%

Example M56 a)-e)

For the preparation of a PS-VA mixture, 0.45% of the polymerisablecompound of the formula a), b), c), d) or e)

are added to 99.55% of the mixture according to Example M55.

Example M57

BCH-32 3.00% Clearing point [° C.]: 70.5 CC-3-V 28.00% Δn [589 nm, 20°C.]: 0.1064 CC-3-V1 10.00% Δε [1 kHz, 20° C.]: −2.9 CCY-3-O1 6.00% γ₁[mPa · s, 20° C.]: 86 CCY-3-O2 11.50% K₁ [pN, 20° C.]: 13.9 CPY-3-O212.00% K₃ [pN, 20° C.]: 16.4 CY-3-O2 10.50% V₀ [20° C., V]: 2.53PP-1-2V1 7.00% PY-3-O2 12.00%

Example M58

0.02% of the compound of the formula

are added to the VA mixture according to Example M57 for stabilization.

Example M59

CC-3-V 29.00% Clearing point [° C.]: 80.5 CY-3-O2 13.00% Δn [589 nm, 20°C.]: 0.1072 CY-5-O2 2.00% Δε [1 kHz, 20° C.]: −4.4 CCY-3-O2 9.00% γ₁[mPa · s, 20° C.]: 131 CCY-4-O2 9.00% K₁ [pN, 20° C.]: 14.3 CCY-5-O23.00% K₃ [pN, 20° C.]: 15.9 CPY-2-O2 9.50% V₀ [20° C., V]: 2.00 CPY-3-O29.50% PYP-2-3 2.50% PY-3-O2 10.00% CCY-3-O1 3.50%

Example M60

0.025% of the compound of the formula

are added to the FFS mixture according to Example M59 for stabilization.

Example M61

CC-3-V 23.50% Clearing point [° C.]: 77.8 CCP-V-1 15.00% Δn [589 nm, 20°C.]: 0.1089 CCY-3-O2 3.00% Δε [1 kHz, 20° C.]: −2.9 CCY-4-O2 13.50% γ₁[mPa · s, 20° C.]: 108 CPY-2-O2 2.00% K₁ [pN, 20° C.]: 12.3 CY-3-O29.00% K₃ [pN, 20° C.]: 14.2 CY-5-O2 15.00% V₀ [20° C., V]: 2.33 PY-3-O22.00% PYP-2-3 4.00% PYP-2-4 13.00%

Example M62

BCH-32 1.50% Clearing point [° C.]: 74.4 CC-3-V 30.00% Δn [589 nm, 20°C.]: 0.1051 CC-3-V1 9.00% Δε [1 kHz, 20° C.]: −3.5 CCY-3-O1 7.00% γ₁[mPa · s, 20° C.]: 94 CCY-3-O2 11.00% K₁ [pN, 20° C.]: 13.4 CPY-2-O211.00% K₃ [pN, 20° C.]: 14.9 CPY-3-O2 11.00% V₀ [20° C., V]: 2.18PY-3-O2 15.00% Y-4O-O4 4.50%

Example M63

0.01% of the compound of the formula

are added to the VA mixture according to Example M62 for stabilization.

Example M64

BCH-32 4.50% Clearing point [° C.]: 74.2 CC-3-V 21.00% Δn [589 nm, 20°C.]: 0.1028 CC-3-V1 10.50% Δε [1 kHz, 20° C.]: −3.4 CCH-23 6.00% γ₁ [mPa· s, 20° C.]: 96 CCY-3-O1 6.00% K₁ [pN, 20° C.]: 14.0 CCY-3-O2 12.50% K₃[pN, 20° C.]: 16.0 CPY-2-O2 5.00% V₀ [20° C., V]: 2.29 CPY-3-O2 9.00%CY-3-O2 10.50% PY-3-O2 15.00%

Example M65

For the preparation of a PS-VA mixture, 0.01% Irganox-1076 of BASF and0.3% of the polymerisable compound of the formula

are added to the VA mixture according to Example M64.

Example M66

CC-3-V 36.00% Clearing point [° C.]: 77.8 CCP-V-1 5.50% Δn [589 nm, 20°C.]: 0.1046 CCY-3-O2 12.50% Δε [1 kHz, 20° C.]: −3.4 CPY-2-O2 11.00% γ₁[mPa · s, 20° C.]: 94 CPY-3-O2 11.00% K₁ [pN, 20° C.]: 13.3 CY-5-O29.50% K₃ [pN, 20° C.]: 15.2 PY-3-O2 14.50% V₀ [20° C., V]: 2.25

Example M67

0.01% of the compound of the formula

are added to the VA mixture according to Example M66 for stabilization.

Example M68

BCH-32 1.50% Clearing point [° C.]: 74.4 CC-3-V 30.00% Δn [589 nm, 20°C.]: 0.1051 CC-3-V1 9.00% Δε [1 kHz, 20° C.]: −3.5 CCY-3-O1 7.00% γ₁[mPa · s, 20° C.]: 94 CCY-3-O2 11.00% K₁ [pN, 20° C.]: 13.4 CPY-2-O211.00% K₃ [pN, 20° C.]: 14.9 CPY-3-O2 11.00% V₀ [20° C., V]: 2.18PY-3-O2 15.00% Y-4O-O4 4.50%

Example M69

0.01% of the compound of the formula

are added to the VA mixture according to Example M68 for stabilization.

Example M70

BCH-32 4.00% Clearing point [° C.]: 74.8 CC-3-V1 8.00% Δn [589 nm, 20°C.]: 0.1057 CCH-23 13.00% Δε [1 kHz, 20° C.]: −3.5 CCH-34 7.00% γ₁ [mPa· s, 20° C.]: 115 CCH-35 7.00% K₁ [pN, 20° C.]: 14.8 CCY-3-O2 13.00% K₃[pN, 20° C.]: 15.8 CPY-2-O2 7.00% V₀ [20° C., V]: 2.23 CPY-3-O2 12.00%CY-3-O2 12.00% PCH-301 2.00 PY-3-O2 15.00

Example M71

For the preparation of a PS-VA mixture, 0.4% of the polymerisablecompound of the formula

are added to the VA mixture according to Example M70.

Example M72

For the preparation of a PS-VA mixture, 0.35% of the polymerisablecompound of the formula

are added to the VA mixture according to Example M70.

Example M73

CC-3-V 28.00% Clearing point [° C.]: 77.2 CC-3-V1 4.00% Δn [589 nm, 20°C.]: 0.1053 CCH-34 7.00% Δε [1 kHz, 20° C.]: −3.4 CCY-3-1 2.00% γ₁ [mPa· s, 20° C.]: 105 CCY-3-O3 12.00% K₁ [pN, 20° C.]: 14.0 CCY-4-O2 5.00%K₃ [pN, 20° C.]: 14.2 CPY-2-O2 12.00% V₀ [20° C., V]: 2.17 CPY-3-O210.00% PY-3-O2 10.00% PY-4-O2 10.00%

Example M74

BCH-32 6.00% Clearing point [° C.]: 76.6 CCH-23 16.00% Δn [589 nm, 20°C.]: 0.0935 CCH-301 3.00% Δε [1 kHz, 20° C.]: −2.6 CCH-34 6.00% γ₁ [mPa· s, 20° C.]: 107 CCH-35 6.00% K₁ [pN, 20° C.]: 14.8 CCP-3-1 12.00% K₃[pN, 20° C.]: 15.4 CY-3-O2 15.00% V₀ [20° C., V]: 2.59 CCY-3-O1 5.00%CCY-3-O2 8.00% CPY-3-O2 8.50% PCH-302 5.00% PY-1-O4 3.50% PY-4-O2 6.00%

Example M75

BCH-32 8.00% Clearing point [° C.]: 75.5 CCH-23 15.00% Δn [589 nm, 20°C.]: 0.0940 CCH-301 9.00% Δε [1 kHz, 20° C.]: −2.3 CCH-34 5.00% γ₁ [mPa· s, 20° C.]: 95 CCH-35 5.00% K₁ [pN, 20° C.]: 14.4 CCP-3-1 8.00% K₃[pN, 20° C.]: 14.1 CCP-3-3 3.50% V₀ [20° C., V]: 2.61 CCY-3-O1 5.00%CCY-3-O2 8.00% CPY-2-O2 6.00% CPY-3-O2 8.00% PCH-302 6.00% PY-1-O4 2.50%PY-4-O2 4.00% Y-4O-O4 7.00%

Example M76

BCH-32 8.00% Clearing point [° C.]: 76.4 CCH-23 15.00% Δn [589 nm, 20°C.]: 0.0951 CCH-301 5.50% Δε [1 kHz, 20° C.]: −2.4 CCH-34 5.00% γ₁ [mPa· s, 20° C.]: 96 CCH-35 5.00% K₁ [pN, 20° C.]: 15.1 CCP-3-1 12.00% K₃[pN, 20° C.]: 15.0 CCY-3-O1 4.00% V₀ [20° C., V]: 2.61 CCY-3-O2 6.00%CPY-3-O2 8.00% CLY-3-O2 8.00% PCH-302 8.00% PY-1-O4 3.50% PY-4-O2 4.00%Y-4O-O4 8.00%

Example M77

0.01% of the compound of the formula

are added to the VA mixture according to Example M71 for stabilization.

What is claimed is:
 1. A liquid-crystalline medium comprising at leastone compound of the formula I,

in which R¹ and R¹* each, independently of one another, denote an alkylor alkoxy radical having 1 to 15 C atoms, where, in addition, one ormore CH₂ groups in these radicals may each be replaced, independently ofone another, by —C≡C—, —CF₂O—, —CH═CH—,

 —O—, —CO—O—, —O—CO— in such a way that O atoms are not linked directlyto one another, and in which, in addition, one or more H atoms may bereplaced by halogen, Z¹ denotes a single bond, —CH₂CH₂—, —CH═CH—,—CH₂O—, —OCH₂—, —CF₂O—, —OCF₂—, —COO—, —OCO—, —C₂F₄—, —CF═CF—,—CH═CHCHO—, L¹ and L² each, independently of one another, denote F, Cl,CF₃ or CHF₂.
 2. A liquid-crystalline medium according to claim 1comprising at least two compounds of the formula I.
 3. Aliquid-crystalline medium according to claim 1 comprising at least threecompounds of the formula I.
 4. A liquid-crystalline medium according toclaim 1, wherein L¹ and L² each denote fluorine.
 5. A liquid-crystallinemedium according to claim 1, wherein Z¹ denotes a single bond.
 6. Aliquid-crystalline medium according to claim 1 comprising at least onecompound of the formula I-1 to I-145,


7. A liquid-crystalline medium according to claim 6 comprising at leastone compound of a formula selected from the group consisting of I-1,I-3, I-7, I-13, I-15, I-19, I-25 and I-26.
 8. A liquid-crystallinemedium according to claim 7 comprising at least two compounds selectedfrom the group consisting of the formulas I-1, I-3, I-7, I-13, I-15,I-19, I-25 and I-26.
 9. A liquid-crystalline medium according to claim1, wherein the proportion of one or more compounds of the formula I inthe mixture as a whole is 5-65% by weight.
 10. A liquid-crystallinemedium according to claim 1 further comprising one or more compoundsselected from the group of the compounds of the formulae IIA, IIB andIIC,

in which R^(2A), R^(2B) and R^(2C) each, independently of one another,denote H, an alkyl radical having up to 15 C atoms which isunsubstituted, monosubstituted by CN or CF₃ or at least monosubstitutedby halogen, where, in addition, one or more CH₂ groups in these radicalsmay be replaced by —O—, —S—,

 —C≡c—, —CF₂O—, —OCF₂—, —OC—O— or —O—CO— in such a way that O atoms arenot linked directly to one another, L¹⁻⁴ each, independently of oneanother, denote F or Cl, Z² and Z^(2′) each, independently of oneanother, denote a single bond, —CH₂CH₂—, —CH═CH—, —CF₂O—, —OCF₂—,—CH₂O—, —OCH₂—, —COO—, —OCO—, —C₂F₄—, —CF═CF—, —CH═CHCH₂O—, denotes 1 or2, q denotes 1 or 2, and v denotes 1 to
 6. 11. A liquid-crystallinemedium according to claim 1 further comprising one or more compounds ofthe formula III,

in which R³¹ and R³² each, independently of one another, denote astraight-chain alkyl, alkoxyalkyl or alkoxy radical having up to 12 Catoms, and

denotes

Z³ denotes a single bond, —CH₂CH₂—, —CH═CH—, —CF₂O—, —OCF₂—, —CH₂O—,—OCH₂—, —COO—, —COO—, —C₂F₄—, —C₄H₈—, —CF═CF—.
 12. A liquid-crystallinemedium according to claim 1 further comprising one or more compounds ofthe formula L-1 to L-11,

in which R, R¹ and R² each, independently of one another, have themeanings indicated for R^(2A) in claim 10, and alkyl denotes an alkylradical having 1-6 C atoms, and s denotes 1 or
 2. 13. Aliquid-crystalline medium according to claim 1 further comprising one ormore terphenyls of the formulae T-1 to T-21,

in which R denotes a straight-chain alkyl or alkoxy radical having 1-7 Catoms, and m denotes 1-6.
 14. A liquid-crystalline medium according toclaim 1 further comprising one or more compounds of the formulae O-1 toO-17,

in which R¹ and R² each, independently of one another, denote H, analkyl radical having up to 15 C atoms which is unsubstituted,monosubstituted by CN or CF₃ or at least monosubstituted by halogen,where, in addition, one or more CH₂ groups in these radicals may bereplaced by —O—, —S—,

 —C≡C—, —CF₂O—, —OCF₂—, —OC—O— or —O—OC— in such a way that O atoms arenot linked directly to one another.
 15. A liquid-crystalline mediumaccording to claim 1 further comprising one or more indane compounds ofthe formula In,

in which R¹¹, R¹², R¹³ denote a straight-chain alkyl, alkoxy,alkoxyalkyl or alkenyl radical having 1-5 C atoms, R¹² and R¹³additionally also denote halogen,

denotes

i denotes 0, 1 or
 2. 16. A liquid-crystalline medium according to claim1 further comprising one or more indane compounds of the formula P4

in which R¹ denotes an alkyl or alkoxy radical having 1 to 15 C atoms,where, in addition, one or more CH₂ groups in these radicals may each bereplaced, independently of one another, by —C≡C—, —CF₂O—, —CH═CH—,

 —O—, —CO—O—, —O—CO— in such a way that O atoms are not linked directlyto one another, and in which, in addition, one or more H atoms may bereplaced by halogen.
 17. A process for the preparation of aliquid-crystalline medium according to claim 1, wherein at least onecompound of the formula I is mixed with at least one furtherliquid-crystalline compound, and one or more additives are optionallyadded.
 18. A process according to claim 17, wherein the additive isselected from the group consisting of stabilisers, antioxidants, UVabsorbers, nanoparticles, microparticles, polymerisable compounds,dopants and free-radical initiators.
 19. An electro-optical displaycomprising the liquid-crystalline medium according to claim
 1. 20. Anelectro-optical display having active-matrix addressing, wherein theelectro-optical display contains, as dielectric, a liquid-crystallinemedium according to claim
 1. 21. The electro-optical display accordingto claim 20, wherein the electro-optical display is a VA, PSA, PS-VA,PALC, FFS, PS-FFS, IPS or PS-IPS display.